CINXE.COM

<!DOCTYPE html> <html class="client-nojs vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-sticky-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-toc-available" lang="en" dir="ltr"> <head> <meta charset="UTF-8"> <title>iCalendar - Wikipedia</title> <script>(function(){var className="client-js vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-sticky-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-toc-available";var cookie=document.cookie.match(/(?:^|; )enwikimwclientpreferences=([^;]+)/);if(cookie){cookie[1].split('%2C').forEach(function(pref){className=className.replace(new RegExp('(^| )'+pref.replace(/-clientpref-\w+$|[^\w-]+/g,'')+'-clientpref-\\w+( |$)'),'$1'+pref+'$2');});}document.documentElement.className=className;}());RLCONF={"wgBreakFrames":false,"wgSeparatorTransformTable":["",""],"wgDigitTransformTable":["",""],"wgDefaultDateFormat":"dmy", "wgMonthNames":["","January","February","March","April","May","June","July","August","September","October","November","December"],"wgRequestId":"962cf422-e9b9-4c70-96db-c9de70c2de6f","wgCanonicalNamespace":"","wgCanonicalSpecialPageName":false,"wgNamespaceNumber":0,"wgPageName":"ICalendar","wgTitle":"ICalendar","wgCurRevisionId":1261197471,"wgRevisionId":1261197471,"wgArticleId":301736,"wgIsArticle":true,"wgIsRedirect":false,"wgAction":"view","wgUserName":null,"wgUserGroups":["*"],"wgCategories":["CS1 maint: others","Articles with short description","Short description is different from Wikidata","Wikipedia articles needing clarification from December 2008","Computer file formats","Calendaring standards","Internet Standards"],"wgPageViewLanguage":"en","wgPageContentLanguage":"en","wgPageContentModel":"wikitext","wgRelevantPageName":"ICalendar","wgRelevantArticleId":301736,"wgIsProbablyEditable":true,"wgRelevantPageIsProbablyEditable":true,"wgRestrictionEdit":[],"wgRestrictionMove":[], "wgNoticeProject":"wikipedia","wgCiteReferencePreviewsActive":false,"wgFlaggedRevsParams":{"tags":{"status":{"levels":1}}},"wgMediaViewerOnClick":true,"wgMediaViewerEnabledByDefault":true,"wgPopupsFlags":0,"wgVisualEditor":{"pageLanguageCode":"en","pageLanguageDir":"ltr","pageVariantFallbacks":"en"},"wgMFDisplayWikibaseDescriptions":{"search":true,"watchlist":true,"tagline":false,"nearby":true},"wgWMESchemaEditAttemptStepOversample":false,"wgWMEPageLength":30000,"wgRelatedArticlesCompat":[],"wgEditSubmitButtonLabelPublish":true,"wgULSPosition":"interlanguage","wgULSisCompactLinksEnabled":false,"wgVector2022LanguageInHeader":true,"wgULSisLanguageSelectorEmpty":false,"wgWikibaseItemId":"Q284651","wgCheckUserClientHintsHeadersJsApi":["brands","architecture","bitness","fullVersionList","mobile","model","platform","platformVersion"],"GEHomepageSuggestedEditsEnableTopics":true,"wgGETopicsMatchModeEnabled":false,"wgGEStructuredTaskRejectionReasonTextInputEnabled":false, "wgGELevelingUpEnabledForUser":false};RLSTATE={"ext.globalCssJs.user.styles":"ready","site.styles":"ready","user.styles":"ready","ext.globalCssJs.user":"ready","user":"ready","user.options":"loading","ext.cite.styles":"ready","ext.pygments":"ready","skins.vector.search.codex.styles":"ready","skins.vector.styles":"ready","skins.vector.icons":"ready","jquery.tablesorter.styles":"ready","jquery.makeCollapsible.styles":"ready","ext.wikimediamessages.styles":"ready","ext.visualEditor.desktopArticleTarget.noscript":"ready","ext.uls.interlanguage":"ready","wikibase.client.init":"ready","ext.wikimediaBadges":"ready"};RLPAGEMODULES=["ext.cite.ux-enhancements","ext.pygments.view","mediawiki.page.media","site","mediawiki.page.ready","jquery.tablesorter","jquery.makeCollapsible","mediawiki.toc","skins.vector.js","ext.centralNotice.geoIP","ext.centralNotice.startUp","ext.gadget.ReferenceTooltips","ext.gadget.switcher","ext.urlShortener.toolbar","ext.centralauth.centralautologin","mmv.bootstrap", "ext.popups","ext.visualEditor.desktopArticleTarget.init","ext.visualEditor.targetLoader","ext.echo.centralauth","ext.eventLogging","ext.wikimediaEvents","ext.navigationTiming","ext.uls.interface","ext.cx.eventlogging.campaigns","ext.cx.uls.quick.actions","wikibase.client.vector-2022","ext.checkUser.clientHints","ext.quicksurveys.init","ext.growthExperiments.SuggestedEditSession"];</script> <script>(RLQ=window.RLQ||[]).push(function(){mw.loader.impl(function(){return["user.options@12s5i",function($,jQuery,require,module){mw.user.tokens.set({"patrolToken":"+\\","watchToken":"+\\","csrfToken":"+\\"}); }];});});</script> <link rel="stylesheet" href="/w/load.php?lang=en&modules=ext.cite.styles%7Cext.pygments%2CwikimediaBadges%7Cext.uls.interlanguage%7Cext.visualEditor.desktopArticleTarget.noscript%7Cext.wikimediamessages.styles%7Cjquery.makeCollapsible.styles%7Cjquery.tablesorter.styles%7Cskins.vector.icons%2Cstyles%7Cskins.vector.search.codex.styles%7Cwikibase.client.init&only=styles&skin=vector-2022"> <script async="" src="/w/load.php?lang=en&modules=startup&only=scripts&raw=1&skin=vector-2022"></script> <meta name="ResourceLoaderDynamicStyles" content=""> <link rel="stylesheet" href="/w/load.php?lang=en&modules=site.styles&only=styles&skin=vector-2022"> <meta name="generator" content="MediaWiki 1.44.0-wmf.6"> <meta name="referrer" content="origin"> <meta name="referrer" content="origin-when-cross-origin"> <meta name="robots" content="max-image-preview:standard"> <meta name="format-detection" content="telephone=no"> <meta name="viewport" content="width=1120"> <meta property="og:title" content="iCalendar - Wikipedia"> <meta property="og:type" content="website"> <link rel="preconnect" href="//upload.wikimedia.org"> <link rel="alternate" media="only screen and (max-width: 640px)" href="//en.m.wikipedia.org/wiki/ICalendar"> <link rel="alternate" type="application/x-wiki" title="Edit this page" href="/w/index.php?title=ICalendar&action=edit"> <link rel="apple-touch-icon" href="/static/apple-touch/wikipedia.png"> <link rel="icon" href="/static/favicon/wikipedia.ico"> <link rel="search" type="application/opensearchdescription+xml" href="/w/rest.php/v1/search" title="Wikipedia (en)"> <link rel="EditURI" type="application/rsd+xml" href="//en.wikipedia.org/w/api.php?action=rsd"> <link rel="canonical" href="https://en.wikipedia.org/wiki/ICalendar"> <link rel="license" href="https://creativecommons.org/licenses/by-sa/4.0/deed.en"> <link rel="alternate" type="application/atom+xml" title="Wikipedia Atom feed" href="/w/index.php?title=Special:RecentChanges&feed=atom"> <link rel="dns-prefetch" href="//meta.wikimedia.org" /> <link rel="dns-prefetch" href="login.wikimedia.org"> </head> <body class="skin--responsive skin-vector skin-vector-search-vue mediawiki ltr sitedir-ltr mw-hide-empty-elt ns-0 ns-subject mw-editable page-ICalendar rootpage-ICalendar skin-vector-2022 action-view"><a class="mw-jump-link" href="#bodyContent">Jump to content</a> <div class="vector-header-container"> <header class="vector-header mw-header"> <div class="vector-header-start"> <nav class="vector-main-menu-landmark" aria-label="Site"> <div id="vector-main-menu-dropdown" class="vector-dropdown vector-main-menu-dropdown vector-button-flush-left vector-button-flush-right" > <input type="checkbox" id="vector-main-menu-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-main-menu-dropdown" class="vector-dropdown-checkbox " aria-label="Main menu" > <label id="vector-main-menu-dropdown-label" for="vector-main-menu-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-menu mw-ui-icon-wikimedia-menu"></span> <span class="vector-dropdown-label-text">Main menu</span> </label> <div class="vector-dropdown-content"> <div id="vector-main-menu-unpinned-container" class="vector-unpinned-container"> <div id="vector-main-menu" class="vector-main-menu vector-pinnable-element"> <div class="vector-pinnable-header vector-main-menu-pinnable-header vector-pinnable-header-unpinned" data-feature-name="main-menu-pinned" data-pinnable-element-id="vector-main-menu" data-pinned-container-id="vector-main-menu-pinned-container" data-unpinned-container-id="vector-main-menu-unpinned-container" > <div class="vector-pinnable-header-label">Main menu</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-main-menu.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-main-menu.unpin">hide</button> </div> <div id="p-navigation" class="vector-menu mw-portlet mw-portlet-navigation" > <div class="vector-menu-heading"> Navigation </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-mainpage-description" class="mw-list-item"><a href="/wiki/Main_Page" title="Visit the main page [z]" accesskey="z"><span>Main page</span></a></li><li id="n-contents" class="mw-list-item"><a href="/wiki/Wikipedia:Contents" title="Guides to browsing Wikipedia"><span>Contents</span></a></li><li id="n-currentevents" class="mw-list-item"><a href="/wiki/Portal:Current_events" title="Articles related to current events"><span>Current events</span></a></li><li id="n-randompage" class="mw-list-item"><a href="/wiki/Special:Random" title="Visit a randomly selected article [x]" accesskey="x"><span>Random article</span></a></li><li id="n-aboutsite" class="mw-list-item"><a href="/wiki/Wikipedia:About" title="Learn about Wikipedia and how it works"><span>About Wikipedia</span></a></li><li id="n-contactpage" class="mw-list-item"><a href="//en.wikipedia.org/wiki/Wikipedia:Contact_us" title="How to contact Wikipedia"><span>Contact us</span></a></li> </ul> </div> </div> <div id="p-interaction" class="vector-menu mw-portlet mw-portlet-interaction" > <div class="vector-menu-heading"> Contribute </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-help" class="mw-list-item"><a href="/wiki/Help:Contents" title="Guidance on how to use and edit Wikipedia"><span>Help</span></a></li><li id="n-introduction" class="mw-list-item"><a href="/wiki/Help:Introduction" title="Learn how to edit Wikipedia"><span>Learn to edit</span></a></li><li id="n-portal" class="mw-list-item"><a href="/wiki/Wikipedia:Community_portal" title="The hub for editors"><span>Community portal</span></a></li><li id="n-recentchanges" class="mw-list-item"><a href="/wiki/Special:RecentChanges" title="A list of recent changes to Wikipedia [r]" accesskey="r"><span>Recent changes</span></a></li><li id="n-upload" class="mw-list-item"><a href="/wiki/Wikipedia:File_upload_wizard" title="Add images or other media for use on Wikipedia"><span>Upload file</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> <a href="/wiki/Main_Page" class="mw-logo"> <img class="mw-logo-icon" src="/static/images/icons/wikipedia.png" alt="" aria-hidden="true" height="50" width="50"> <span class="mw-logo-container skin-invert"> <img class="mw-logo-wordmark" alt="Wikipedia" src="/static/images/mobile/copyright/wikipedia-wordmark-en.svg" style="width: 7.5em; height: 1.125em;"> <img class="mw-logo-tagline" alt="The Free Encyclopedia" src="/static/images/mobile/copyright/wikipedia-tagline-en.svg" width="117" height="13" style="width: 7.3125em; height: 0.8125em;"> </span> </a> </div> <div class="vector-header-end"> <div id="p-search" role="search" class="vector-search-box-vue vector-search-box-collapses vector-search-box-show-thumbnail vector-search-box-auto-expand-width vector-search-box"> <a href="/wiki/Special:Search" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only search-toggle" title="Search Wikipedia [f]" accesskey="f"><span class="vector-icon mw-ui-icon-search mw-ui-icon-wikimedia-search"></span> <span>Search</span> </a> <div class="vector-typeahead-search-container"> <div class="cdx-typeahead-search cdx-typeahead-search--show-thumbnail cdx-typeahead-search--auto-expand-width"> <form action="/w/index.php" id="searchform" class="cdx-search-input cdx-search-input--has-end-button"> <div id="simpleSearch" class="cdx-search-input__input-wrapper" data-search-loc="header-moved"> <div class="cdx-text-input cdx-text-input--has-start-icon"> <input class="cdx-text-input__input" type="search" name="search" placeholder="Search Wikipedia" aria-label="Search Wikipedia" autocapitalize="sentences" title="Search Wikipedia [f]" accesskey="f" id="searchInput" > <span class="cdx-text-input__icon cdx-text-input__start-icon"></span> </div> <input type="hidden" name="title" value="Special:Search"> </div> <button class="cdx-button cdx-search-input__end-button">Search</button> </form> </div> </div> </div> <nav class="vector-user-links vector-user-links-wide" aria-label="Personal tools"> <div class="vector-user-links-main"> <div id="p-vector-user-menu-preferences" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-userpage" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <nav class="vector-appearance-landmark" aria-label="Appearance"> <div id="vector-appearance-dropdown" class="vector-dropdown " title="Change the appearance of the page's font size, width, and color" > <input type="checkbox" id="vector-appearance-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-appearance-dropdown" class="vector-dropdown-checkbox " aria-label="Appearance" > <label id="vector-appearance-dropdown-label" for="vector-appearance-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-appearance mw-ui-icon-wikimedia-appearance"></span> <span class="vector-dropdown-label-text">Appearance</span> </label> <div class="vector-dropdown-content"> <div id="vector-appearance-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <div id="p-vector-user-menu-notifications" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-overflow" class="vector-menu mw-portlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="https://donate.wikimedia.org/?wmf_source=donate&wmf_medium=sidebar&wmf_campaign=en.wikipedia.org&uselang=en" class=""><span>Donate</span></a> </li> <li id="pt-createaccount-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Special:CreateAccount&returnto=ICalendar" title="You are encouraged to create an account and log in; however, it is not mandatory" class=""><span>Create account</span></a> </li> <li id="pt-login-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Special:UserLogin&returnto=ICalendar" title="You're encouraged to log in; however, it's not mandatory. [o]" accesskey="o" class=""><span>Log in</span></a> </li> </ul> </div> </div> </div> <div id="vector-user-links-dropdown" class="vector-dropdown vector-user-menu vector-button-flush-right vector-user-menu-logged-out" title="Log in and more options" > <input type="checkbox" id="vector-user-links-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-user-links-dropdown" class="vector-dropdown-checkbox " aria-label="Personal tools" > <label id="vector-user-links-dropdown-label" for="vector-user-links-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-ellipsis mw-ui-icon-wikimedia-ellipsis"></span> <span class="vector-dropdown-label-text">Personal tools</span> </label> <div class="vector-dropdown-content"> <div id="p-personal" class="vector-menu mw-portlet mw-portlet-personal user-links-collapsible-item" title="User menu" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport" class="user-links-collapsible-item mw-list-item"><a href="https://donate.wikimedia.org/?wmf_source=donate&wmf_medium=sidebar&wmf_campaign=en.wikipedia.org&uselang=en"><span>Donate</span></a></li><li id="pt-createaccount" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Special:CreateAccount&returnto=ICalendar" title="You are encouraged to create an account and log in; however, it is not mandatory"><span class="vector-icon mw-ui-icon-userAdd mw-ui-icon-wikimedia-userAdd"></span> <span>Create account</span></a></li><li id="pt-login" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Special:UserLogin&returnto=ICalendar" title="You're encouraged to log in; however, it's not mandatory. [o]" accesskey="o"><span class="vector-icon mw-ui-icon-logIn mw-ui-icon-wikimedia-logIn"></span> <span>Log in</span></a></li> </ul> </div> </div> <div id="p-user-menu-anon-editor" class="vector-menu mw-portlet mw-portlet-user-menu-anon-editor" > <div class="vector-menu-heading"> Pages for logged out editors <a href="/wiki/Help:Introduction" aria-label="Learn more about editing"><span>learn more</span></a> </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-anoncontribs" class="mw-list-item"><a href="/wiki/Special:MyContributions" title="A list of edits made from this IP address [y]" accesskey="y"><span>Contributions</span></a></li><li id="pt-anontalk" class="mw-list-item"><a href="/wiki/Special:MyTalk" title="Discussion about edits from this IP address [n]" accesskey="n"><span>Talk</span></a></li> </ul> </div> </div> </div> </div> </nav> </div> </header> </div> <div class="mw-page-container"> <div class="mw-page-container-inner"> <div class="vector-sitenotice-container"> <div id="siteNotice"></div> </div> <div class="vector-column-start"> <div class="vector-main-menu-container"> <div id="mw-navigation"> <nav id="mw-panel" class="vector-main-menu-landmark" aria-label="Site"> <div id="vector-main-menu-pinned-container" class="vector-pinned-container"> </div> </nav> </div> </div> <div class="vector-sticky-pinned-container"> <nav id="mw-panel-toc" aria-label="Contents" data-event-name="ui.sidebar-toc" class="mw-table-of-contents-container vector-toc-landmark"> <div id="vector-toc-pinned-container" class="vector-pinned-container"> <div id="vector-toc" class="vector-toc vector-pinnable-element"> <div class="vector-pinnable-header vector-toc-pinnable-header vector-pinnable-header-pinned" data-feature-name="toc-pinned" data-pinnable-element-id="vector-toc" > <h2 class="vector-pinnable-header-label">Contents</h2> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-toc.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-toc.unpin">hide</button> </div> <ul class="vector-toc-contents" id="mw-panel-toc-list"> <li id="toc-mw-content-text" class="vector-toc-list-item vector-toc-level-1"> <a href="#" class="vector-toc-link"> <div class="vector-toc-text">(Top)</div> </a> </li> <li id="toc-History" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#History"> <div class="vector-toc-text"> <span class="vector-toc-numb">1</span> <span>History</span> </div> </a> <ul id="toc-History-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Design" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Design"> <div class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>Design</span> </div> </a> <ul id="toc-Design-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Extensions" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Extensions"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Extensions</span> </div> </a> <ul id="toc-Extensions-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-List_of_components,_properties,_and_parameters" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#List_of_components,_properties,_and_parameters"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>List of components, properties, and parameters</span> </div> </a> <ul id="toc-List_of_components,_properties,_and_parameters-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Other_representations" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Other_representations"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>Other representations</span> </div> </a> <ul id="toc-Other_representations-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-See_also" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#See_also"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>See also</span> </div> </a> <ul id="toc-See_also-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-References" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#References"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>References</span> </div> </a> <ul id="toc-References-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-External_links" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#External_links"> <div class="vector-toc-text"> <span class="vector-toc-numb">8</span> <span>External links</span> </div> </a> <ul id="toc-External_links-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" > <input type="checkbox" id="vector-page-titlebar-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-titlebar-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-page-titlebar-toc-label" for="vector-page-titlebar-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">Toggle the table of contents</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-titlebar-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <h1 id="firstHeading" class="firstHeading mw-first-heading">iCalendar</h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang" > <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="Go to an article in another language. Available in 14 languages" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-14" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">14 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/ICalendar" title="ICalendar – Catalan" lang="ca" hreflang="ca" data-title="ICalendar" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/ICalendar" title="ICalendar – Czech" lang="cs" hreflang="cs" data-title="ICalendar" data-language-autonym="Čeština" data-language-local-name="Czech" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/ICalendar" title="ICalendar – German" lang="de" hreflang="de" data-title="ICalendar" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/ICalendar" title="ICalendar – Spanish" lang="es" hreflang="es" data-title="ICalendar" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/ICalendar" title="ICalendar – French" lang="fr" hreflang="fr" data-title="ICalendar" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/%EC%95%84%EC%9D%B4%EC%BA%98%EB%A6%B0%EB%8D%94" title="아이캘린더 – Korean" lang="ko" hreflang="ko" data-title="아이캘린더" data-language-autonym="한국어" data-language-local-name="Korean" class="interlanguage-link-target"><span>한국어</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/ICalendar" title="ICalendar – Italian" lang="it" hreflang="it" data-title="ICalendar" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/ICalendar" title="ICalendar – Japanese" lang="ja" hreflang="ja" data-title="ICalendar" data-language-autonym="日本語" data-language-local-name="Japanese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-no mw-list-item"><a href="https://no.wikipedia.org/wiki/ICalendar" title="ICalendar – Norwegian Bokmål" lang="nb" hreflang="nb" data-title="ICalendar" data-language-autonym="Norsk bokmål" data-language-local-name="Norwegian Bokmål" class="interlanguage-link-target"><span>Norsk bokmål</span></a></li><li class="interlanguage-link interwiki-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/ICalendar" title="ICalendar – Polish" lang="pl" hreflang="pl" data-title="ICalendar" data-language-autonym="Polski" data-language-local-name="Polish" class="interlanguage-link-target"><span>Polski</span></a></li><li class="interlanguage-link interwiki-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/ICalendar" title="ICalendar – Finnish" lang="fi" hreflang="fi" data-title="ICalendar" data-language-autonym="Suomi" data-language-local-name="Finnish" class="interlanguage-link-target"><span>Suomi</span></a></li><li class="interlanguage-link interwiki-sv mw-list-item"><a href="https://sv.wikipedia.org/wiki/ICalendar" title="ICalendar – Swedish" lang="sv" hreflang="sv" data-title="ICalendar" data-language-autonym="Svenska" data-language-local-name="Swedish" class="interlanguage-link-target"><span>Svenska</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/ICalendar" title="ICalendar – Ukrainian" lang="uk" hreflang="uk" data-title="ICalendar" data-language-autonym="Українська" data-language-local-name="Ukrainian" class="interlanguage-link-target"><span>Українська</span></a></li><li class="interlanguage-link interwiki-zh mw-list-item"><a href="https://zh.wikipedia.org/wiki/ICalendar" title="ICalendar – Chinese" lang="zh" hreflang="zh" data-title="ICalendar" data-language-autonym="中文" data-language-local-name="Chinese" class="interlanguage-link-target"><span>中文</span></a></li> </ul> <div class="after-portlet after-portlet-lang"><span class="wb-langlinks-edit wb-langlinks-link"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q284651#sitelinks-wikipedia" title="Edit interlanguage links" class="wbc-editpage">Edit links</a></span></div> </div> </div> </div> </header> <div class="vector-page-toolbar"> <div class="vector-page-toolbar-container"> <div id="left-navigation"> <nav aria-label="Namespaces"> <div id="p-associated-pages" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-associated-pages" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-nstab-main" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/ICalendar" title="View the content page [c]" accesskey="c"><span>Article</span></a></li><li id="ca-talk" class="vector-tab-noicon mw-list-item"><a href="/wiki/Talk:ICalendar" rel="discussion" title="Discuss improvements to the content page [t]" accesskey="t"><span>Talk</span></a></li> </ul> </div> </div> <div id="vector-variants-dropdown" class="vector-dropdown emptyPortlet" > <input type="checkbox" id="vector-variants-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-variants-dropdown" class="vector-dropdown-checkbox " aria-label="Change language variant" > <label id="vector-variants-dropdown-label" for="vector-variants-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">English</span> </label> <div class="vector-dropdown-content"> <div id="p-variants" class="vector-menu mw-portlet mw-portlet-variants emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> </div> </div> </nav> </div> <div id="right-navigation" class="vector-collapsible"> <nav aria-label="Views"> <div id="p-views" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-views" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-view" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/ICalendar"><span>Read</span></a></li><li id="ca-edit" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=ICalendar&action=edit" title="Edit this page [e]" accesskey="e"><span>Edit</span></a></li><li id="ca-history" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=ICalendar&action=history" title="Past revisions of this page [h]" accesskey="h"><span>View history</span></a></li> </ul> </div> </div> </nav> <nav class="vector-page-tools-landmark" aria-label="Page tools"> <div id="vector-page-tools-dropdown" class="vector-dropdown vector-page-tools-dropdown" > <input type="checkbox" id="vector-page-tools-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-tools-dropdown" class="vector-dropdown-checkbox " aria-label="Tools" > <label id="vector-page-tools-dropdown-label" for="vector-page-tools-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">Tools</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-tools-unpinned-container" class="vector-unpinned-container"> <div id="vector-page-tools" class="vector-page-tools vector-pinnable-element"> <div class="vector-pinnable-header vector-page-tools-pinnable-header vector-pinnable-header-unpinned" data-feature-name="page-tools-pinned" data-pinnable-element-id="vector-page-tools" data-pinned-container-id="vector-page-tools-pinned-container" data-unpinned-container-id="vector-page-tools-unpinned-container" > <div class="vector-pinnable-header-label">Tools</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-page-tools.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-page-tools.unpin">hide</button> </div> <div id="p-cactions" class="vector-menu mw-portlet mw-portlet-cactions emptyPortlet vector-has-collapsible-items" title="More options" > <div class="vector-menu-heading"> Actions </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-more-view" class="selected vector-more-collapsible-item mw-list-item"><a href="/wiki/ICalendar"><span>Read</span></a></li><li id="ca-more-edit" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=ICalendar&action=edit" title="Edit this page [e]" accesskey="e"><span>Edit</span></a></li><li id="ca-more-history" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=ICalendar&action=history"><span>View history</span></a></li> </ul> </div> </div> <div id="p-tb" class="vector-menu mw-portlet mw-portlet-tb" > <div class="vector-menu-heading"> General </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="t-whatlinkshere" class="mw-list-item"><a href="/wiki/Special:WhatLinksHere/ICalendar" title="List of all English Wikipedia pages containing links to this page [j]" accesskey="j"><span>What links here</span></a></li><li id="t-recentchangeslinked" class="mw-list-item"><a href="/wiki/Special:RecentChangesLinked/ICalendar" rel="nofollow" title="Recent changes in pages linked from this page [k]" accesskey="k"><span>Related changes</span></a></li><li id="t-upload" class="mw-list-item"><a href="/wiki/Wikipedia:File_Upload_Wizard" title="Upload files [u]" accesskey="u"><span>Upload file</span></a></li><li id="t-specialpages" class="mw-list-item"><a href="/wiki/Special:SpecialPages" title="A list of all special pages [q]" accesskey="q"><span>Special pages</span></a></li><li id="t-permalink" class="mw-list-item"><a href="/w/index.php?title=ICalendar&oldid=1261197471" title="Permanent link to this revision of this page"><span>Permanent link</span></a></li><li id="t-info" class="mw-list-item"><a href="/w/index.php?title=ICalendar&action=info" title="More information about this page"><span>Page information</span></a></li><li id="t-cite" class="mw-list-item"><a href="/w/index.php?title=Special:CiteThisPage&page=ICalendar&id=1261197471&wpFormIdentifier=titleform" title="Information on how to cite this page"><span>Cite this page</span></a></li><li id="t-urlshortener" class="mw-list-item"><a href="/w/index.php?title=Special:UrlQ%C4%B1sald%C4%B1c%C4%B1s%C4%B1&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FICalendar"><span>Get shortened URL</span></a></li><li id="t-urlshortener-qrcode" class="mw-list-item"><a href="/w/index.php?title=Special:QrKodu&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FICalendar"><span>Download QR code</span></a></li> </ul> </div> </div> <div id="p-coll-print_export" class="vector-menu mw-portlet mw-portlet-coll-print_export" > <div class="vector-menu-heading"> Print/export </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="coll-download-as-rl" class="mw-list-item"><a href="/w/index.php?title=Special:DownloadAsPdf&page=ICalendar&action=show-download-screen" title="Download this page as a PDF file"><span>Download as PDF</span></a></li><li id="t-print" class="mw-list-item"><a href="/w/index.php?title=ICalendar&printable=yes" title="Printable version of this page [p]" accesskey="p"><span>Printable version</span></a></li> </ul> </div> </div> <div id="p-wikibase-otherprojects" class="vector-menu mw-portlet mw-portlet-wikibase-otherprojects" > <div class="vector-menu-heading"> In other projects </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="t-wikibase" class="wb-otherproject-link wb-otherproject-wikibase-dataitem mw-list-item"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q284651" title="Structured data on this page hosted by Wikidata [g]" accesskey="g"><span>Wikidata item</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> </div> </div> </div> <div class="vector-column-end"> <div class="vector-sticky-pinned-container"> <nav class="vector-page-tools-landmark" aria-label="Page tools"> <div id="vector-page-tools-pinned-container" class="vector-pinned-container"> </div> </nav> <nav class="vector-appearance-landmark" aria-label="Appearance"> <div id="vector-appearance-pinned-container" class="vector-pinned-container"> <div id="vector-appearance" class="vector-appearance vector-pinnable-element"> <div class="vector-pinnable-header vector-appearance-pinnable-header vector-pinnable-header-pinned" data-feature-name="appearance-pinned" data-pinnable-element-id="vector-appearance" data-pinned-container-id="vector-appearance-pinned-container" data-unpinned-container-id="vector-appearance-unpinned-container" > <div class="vector-pinnable-header-label">Appearance</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-appearance.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-appearance.unpin">hide</button> </div> </div> </div> </nav> </div> </div> <div id="bodyContent" class="vector-body" aria-labelledby="firstHeading" data-mw-ve-target-container> <div class="vector-body-before-content"> <div class="mw-indicators"> </div> <div id="siteSub" class="noprint">From Wikipedia, the free encyclopedia</div> </div> <div id="contentSub"><div id="mw-content-subtitle"></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Computer file format for calendar information</div> <style data-mw-deduplicate="TemplateStyles:r1236090951">.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}</style><div role="note" class="hatnote navigation-not-searchable">For Apple's calendar application, previously named iCal, see <a href="/wiki/Calendar_(Apple)" title="Calendar (Apple)">Calendar (Apple)</a>.</div> <style data-mw-deduplicate="TemplateStyles:r1257001546">.mw-parser-output .infobox-subbox{padding:0;border:none;margin:-3px;width:auto;min-width:100%;font-size:100%;clear:none;float:none;background-color:transparent}.mw-parser-output .infobox-3cols-child{margin:auto}.mw-parser-output .infobox .navbar{font-size:100%}@media screen{html.skin-theme-clientpref-night .mw-parser-output .infobox-full-data:not(.notheme)>div:not(.notheme)[style]{background:#1f1f23!important;color:#f8f9fa}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .infobox-full-data:not(.notheme) div:not(.notheme){background:#1f1f23!important;color:#f8f9fa}}@media(min-width:640px){body.skin--responsive .mw-parser-output .infobox-table{display:table!important}body.skin--responsive .mw-parser-output .infobox-table>caption{display:table-caption!important}body.skin--responsive .mw-parser-output .infobox-table>tbody{display:table-row-group}body.skin--responsive .mw-parser-output .infobox-table tr{display:table-row!important}body.skin--responsive .mw-parser-output .infobox-table th,body.skin--responsive .mw-parser-output .infobox-table td{padding-left:inherit;padding-right:inherit}}</style><table class="infobox"><caption class="infobox-title" style="padding-bottom:0.15em;">ICalendar</caption><tbody><tr><th scope="row" class="infobox-label" style="line-height:1.2em; padding-right:0.65em;"><a href="/wiki/Filename_extension" title="Filename extension">Filename extension</a></th><td class="infobox-data" style="line-height:1.35em;"><style data-mw-deduplicate="TemplateStyles:r886049734">.mw-parser-output .monospaced{font-family:monospace,monospace}</style><div class="monospaced"> .ical, .ics, .ifb, .icalendar</div></td></tr><tr><th scope="row" class="infobox-label" style="line-height:1.2em; padding-right:0.65em;"><a href="/wiki/Media_type" title="Media type">Internet media type</a></th><td class="infobox-data" style="line-height:1.35em;"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><div class="monospaced"> text/calendar</div></td></tr><tr><th scope="row" class="infobox-label" style="line-height:1.2em; padding-right:0.65em;">Type of format</th><td class="infobox-data" style="line-height:1.35em;"><a href="/wiki/Calendar" title="Calendar">Calendar</a> data exchange</td></tr><tr><th scope="row" class="infobox-label" style="line-height:1.2em; padding-right:0.65em;"><a href="/wiki/International_standard" title="International standard">Standard</a></th><td class="infobox-data" style="line-height:1.35em;"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style>RFC <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc5545">5545</a> (Updated by: <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222">RFC <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc5546">5546</a>, <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222">RFC <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc6868">6868</a>, <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222">RFC <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc7529">7529</a>, <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222">RFC <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc7986">7986</a>)</td></tr><tr><th scope="row" class="infobox-label" style="line-height:1.2em; padding-right:0.65em;"><span class="nowrap"><a href="/wiki/Open_file_format" title="Open file format">Open format</a>?</span></th><td class="infobox-data" style="line-height:1.35em;">Yes</td></tr></tbody></table> <p>The <b>Internet Calendaring and Scheduling Core Object Specification</b> (<b>iCalendar</b>) is a <a href="/wiki/Media_type" title="Media type">media type</a> which allows users to store and exchange calendaring and scheduling information such as events, to-dos, journal entries, and free/busy information,<sup id="cite_ref-:0_1-0" class="reference"><a href="#cite_note-:0-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> and together with its associated standards has been a cornerstone of the standardization and interoperability of <a href="/wiki/Digital_calendar" title="Digital calendar">digital calendars</a> across different vendors. Files formatted according to the specification usually have an <a href="/wiki/Filename_extension" title="Filename extension">extension</a> of <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">.ics</span>. With supporting software, such as an <a href="/wiki/Email_client" title="Email client">email reader</a> or <a href="/wiki/Calendaring_software" class="mw-redirect" title="Calendaring software">calendar application</a>, recipients of an iCalendar data file can respond to the sender easily or counter-propose another meeting date/time. The file format is specified in a <a href="/wiki/Internet_standard" class="mw-redirect" title="Internet standard">proposed Internet standard</a> (RFC 5545) for calendar data exchange. The standard and file type are sometimes referred to as "iCal", which was the name of the <a href="/wiki/Apple_Inc." title="Apple Inc.">Apple Inc.</a> calendar program until 2012 (see <a href="/wiki/ICal" class="mw-redirect" title="ICal">iCal</a>), which provides one of the implementations of the standard. </p><p>iCalendar is used and supported by many products, including: </p> <ul><li>general consumer: <a href="/wiki/Calendar_(Apple)" title="Calendar (Apple)">Apple Calendar</a> (formerly iCal), <a href="/wiki/EM_Client" title="EM Client">eM Client</a>, <a href="/wiki/Google_Calendar" title="Google Calendar">Google Calendar</a>, <a href="/wiki/Yahoo!_Calendar" class="mw-redirect" title="Yahoo! Calendar">Yahoo! Calendar</a></li> <li>corporate: <a href="/wiki/HCL_Domino" class="mw-redirect" title="HCL Domino">HCL Domino</a> (formerly IBM Notes and Lotus Notes)<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup></li> <li><a href="/wiki/Free_software" title="Free software">free software</a>: <a href="/wiki/GNOME_Evolution" title="GNOME Evolution">GNOME Evolution</a>, <a href="/wiki/GNU_Emacs" title="GNU Emacs">GNU Emacs</a>, <a href="/wiki/Mozilla_Thunderbird" title="Mozilla Thunderbird">Mozilla Thunderbird</a>, and <a href="/wiki/SeaMonkey" title="SeaMonkey">SeaMonkey</a></li></ul> <p>It is partially supported by <a href="/wiki/Microsoft_Outlook" title="Microsoft Outlook">Microsoft Outlook</a> and <a href="/wiki/Novell_GroupWise" class="mw-redirect" title="Novell GroupWise">Novell GroupWise</a>. </p><p>iCalendar is designed to be independent of the transport protocol. For example, certain events can be sent by traditional email or whole calendar files can be shared and edited by using a <a href="/wiki/WebDav" class="mw-redirect" title="WebDav">WebDav</a> server, or <a href="/wiki/SyncML" title="SyncML">SyncML</a>. Simple web servers (using just the HTTP protocol) are often used to distribute iCalendar data about an event and to publish busy times of an individual. Publishers can embed iCalendar data in web pages using <a href="/wiki/HCalendar" title="HCalendar">hCalendar</a>, a 1:1 <a href="/wiki/Microformats" class="mw-redirect" title="Microformats">microformat</a> representation of iCalendar in semantic <a href="/wiki/XHTML" title="XHTML">(X)</a><a href="/wiki/HTML" title="HTML">HTML</a>. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="History">History</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=ICalendar&action=edit&section=1" title="Edit section: History"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:ICalendarSpecification.png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/c/c0/ICalendarSpecification.png/220px-ICalendarSpecification.png" decoding="async" width="220" height="174" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/c/c0/ICalendarSpecification.png/330px-ICalendarSpecification.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/c/c0/ICalendarSpecification.png/440px-ICalendarSpecification.png 2x" data-file-width="1061" data-file-height="839" /></a><figcaption>iCalendar components and their properties</figcaption></figure> <p>iCalendar was created in 1998<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> by the Calendaring and Scheduling Working Group of the <a href="/wiki/Internet_Engineering_Task_Force" title="Internet Engineering Task Force">Internet Engineering Task Force</a>, chaired by Anik Ganguly of <a href="/wiki/Open_Text_Corporation" class="mw-redirect" title="Open Text Corporation">Open Text Corporation</a>, and was authored by Frank Dawson of <a href="/wiki/Lotus_Development_Corporation" class="mw-redirect" title="Lotus Development Corporation">Lotus Development Corporation</a> and Derik Stenerson of <a href="/wiki/Microsoft_Corporation" class="mw-redirect" title="Microsoft Corporation">Microsoft Corporation</a>. iCalendar data files are <a href="/wiki/Plain_text" title="Plain text">plain text</a> files with the <a href="/wiki/Filename_extension" title="Filename extension">extension</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">.ics</span> or <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">.ifb</span> (for files containing availability information only). RFC 5545 replaced RFC 2445 in September 2009 and now defines the standard. </p><p>iCalendar is heavily based on the earlier <a href="/wiki/VCalendar" class="mw-redirect" title="VCalendar">vCalendar</a> by the <a href="/wiki/Internet_Mail_Consortium" title="Internet Mail Consortium">Internet Mail Consortium</a> (IMC).<sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> It has the .vcs file extension. After iCalendar was released, the Internet Mail Consortium stated that it "hopes that all vCalendar developers take advantage of these new open standards and make their software compatible with both vCalendar 1.0 and iCalendar."<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> </p><p>The memo "Calendar Access Protocol" (<a href="/wiki/Request_for_Comments" title="Request for Comments">RFC</a> 4324) was an initial attempt at a universal system to create real-time calendars, but was eventually abandoned. Instead, iCalendar saw some adoption for such purposes with <i>ad hoc</i> extensions such as GroupDAV and <a href="/wiki/CalDAV" title="CalDAV">CalDAV</a> emerging as informal standards and seeing some adoption in both client and server <a href="/wiki/Software" title="Software">software</a> packages. </p><p>A first effort to simplify iCalendar standards by the <a href="/wiki/IETF" class="mw-redirect" title="IETF">IETF</a> "Calendaring and Scheduling Working Group" (ietf-calsify WG) ended in January 2011 without seeing adoption.<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> The work was then picked up by the "Calendaring Extensions Working Group" (ietf-calext WG).<sup id="cite_ref-8" class="reference"><a href="#cite_note-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Design">Design</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=ICalendar&action=edit&section=2" title="Edit section: Design"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>iCalendar data have the <a href="/wiki/MIME" title="MIME">MIME</a> content type <code class="mw-highlight mw-highlight-lang-text mw-content-ltr" style="" dir="ltr">text/calendar</code>. The filename extension of <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">ics</span> is to be used for files containing calendaring and scheduling information, <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">ifb</span> for files with free or busy time information consistent with this MIME content type. The equivalent file <a href="/wiki/Type_code" class="mw-redirect" title="Type code">type codes</a> in Apple Macintosh operating system environments are <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">iCal</span> and <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">iFBf</span>. </p><p>By default, iCalendar uses the <a href="/wiki/UTF-8" title="UTF-8">UTF-8</a> <a href="/wiki/Character_set" class="mw-redirect" title="Character set">character set</a>; a different character set can be specified using the "charset" MIME parameter (if the transport method used supports MIME, such as <a href="/wiki/Email" title="Email">Email</a> or <a href="/wiki/HTTP" title="HTTP">HTTP</a>). Each line is terminated by <a href="/wiki/Carriage_return" title="Carriage return">CR</a>+<a href="/wiki/Line_feed" class="mw-redirect" title="Line feed">LF</a> (in <a href="/wiki/Hexadecimal" title="Hexadecimal">hexadecimal</a>: <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">0D0A</span>). Lines should be limited to 75 <a href="/wiki/Octet_(computing)" title="Octet (computing)">octets</a> (not characters) long. Where a data item is too long to fit on a single line it can be continued on following lines by starting the continuation lines with a space character (in hex: 20) or a tab character (in hex: 09). Actual line feeds in data items are encoded as a backslash followed by the letter n or N (the bytes <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">5C 6E</span> or <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">5C 4E</span> in UTF-8). </p><p>The iCalendar format is designed to transmit calendar-based data, such as events, and intentionally does not describe what to do with that data. Thus, other programming may be needed to negotiate what to do with this data. A companion standard, "iCalendar Transport-Independent Interoperability" (iTIP) (RFC 2446), defines a protocol for exchanging iCalendar objects for collaborative calendaring and scheduling between "Calendar Users" (CUs) facilitated by an "Organizer" initiating the exchange of data. This standard defines methods such as <code class="mw-highlight mw-highlight-lang-text mw-content-ltr" style="" dir="ltr">PUBLISH</code>, <code class="mw-highlight mw-highlight-lang-text mw-content-ltr" style="" dir="ltr">REQUEST</code>, <code class="mw-highlight mw-highlight-lang-text mw-content-ltr" style="" dir="ltr">REPLY</code>, <code class="mw-highlight mw-highlight-lang-text mw-content-ltr" style="" dir="ltr">ADD</code>, <code class="mw-highlight mw-highlight-lang-text mw-content-ltr" style="" dir="ltr">CANCEL</code>, <code class="mw-highlight mw-highlight-lang-text mw-content-ltr" style="" dir="ltr">REFRESH</code>, <code class="mw-highlight mw-highlight-lang-text mw-content-ltr" style="" dir="ltr">COUNTER</code> (to negotiate a change in the entry), and <code class="mw-highlight mw-highlight-lang-text mw-content-ltr" style="" dir="ltr">DECLINE-COUNTER</code> (to decline the counter-proposal). Another companion standard, "iCalendar Message-based Interoperability Protocol (iMIP)" (RFC 2447), defines a standard method for implementing iTIP on standard Internet email-based transports. The "Guide to Internet Calendaring" (RFC 3283) explains how iCalendar interacts with other calendar computer language (current and future). </p><p>The top-level element in iCalendar is the Calendaring and Scheduling Core Object, a collection of calendar and scheduling information. Typically, this information will consist of a single iCalendar object. However, multiple iCalendar objects can be grouped together. The first line must be <code class="mw-highlight mw-highlight-lang-text mw-content-ltr" style="" dir="ltr">BEGIN:VCALENDAR</code>, and the last line must be <code class="mw-highlight mw-highlight-lang-text mw-content-ltr" style="" dir="ltr">END:VCALENDAR</code>; the contents between these lines is called the "icalbody". The body must include the "<link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">PRODID</span>" and "<link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">VERSION</span>" calendar properties. In addition, it must include at least one calendar component.<sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> </p><p><code class="mw-highlight mw-highlight-lang-text mw-content-ltr" style="" dir="ltr">VERSION:1.0</code> is used to specify that data is in the old vCalendar format. <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">VERSION</span> is 2.0 for the current iCalendar format as of 2016. </p><p>The body of the iCalendar object (the icalbody) contains single-line <i>Calendar Properties</i> that apply to the entire calendar, as well as one or more blocks of multiple lines that each define a <i>Calendar Component</i> such as an event, journal entry, alarm, or one of several other types. Here is a simple example of an iCalendar object with a single calendar containing a single <i>Calendar Component</i>, a "<a href="/wiki/Bastille_Day" title="Bastille Day">Bastille Day</a> Party" event starting at 5pm on July 14, 1997, and ending at 4am the following morning:<sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-highlight mw-highlight-lang-text mw-content-ltr" dir="ltr"><pre><span></span>BEGIN:VCALENDAR VERSION:2.0 PRODID:-//hacksw/handcal//NONSGML v1.0//EN BEGIN:VEVENT UID:uid1@example.com ORGANIZER;CN=John Doe:MAILTO:john.doe@example.com DTSTART:19970714T170000Z DTEND:19970715T040000Z SUMMARY:Bastille Day Party GEO:48.85299;2.36885 END:VEVENT END:VCALENDAR </pre></div> <p>The UID field distributes updates when a scheduled event changes. When the event is first generated a <a href="/wiki/UUID" class="mw-redirect" title="UUID">globally unique</a> identifier is created. If a later event is distributed with the same UID, it replaces the original one. An example UID might be <code>Y2007S2C131M5@example.edu</code>, for the 5th meeting of class 131 in semester 2 at a hypothetical college. Email-style UIDs are now considered bad practice, with a <a href="/wiki/UUID" class="mw-redirect" title="UUID">UUID</a> recommended instead.<sup id="cite_ref-11" class="reference"><a href="#cite_note-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> </p><p>The most common representation of date and time is a <i>tz timestamp</i> such as <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">20010911T124640Z</span> with the format <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced"><year (4 digits)><month (2)><day (2)>T<hour (2)><minute (2)><second (2)>Z</span> for a total fixed length of 16 characters. <i>Z</i> indicates the use of <a href="/wiki/Coordinated_Universal_Time#Time_zones" title="Coordinated Universal Time">UTC</a> (referring to its Zulu time zone).<sup id="cite_ref-12" class="reference"><a href="#cite_note-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> When used in <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">DTSTART</span> and <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">DTEND</span> properties, start times are inclusive while end times are not. This allows an event's end time to be the same as a consecutive event's start without those events overlapping and potentially creating (false) scheduling conflicts.<sup id="cite_ref-13" class="reference"><a href="#cite_note-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup> </p><p>Components include: </p> <ul><li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">VEVENT</span> describes an event, which has a scheduled amount of time on a calendar. Normally, when a user accepts the calendar event, this will cause that time to be considered busy, though an event can be set to be <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">TRANSPARENT</span> to change this interpretation. A <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">VEVENT</span> may include a <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">VALARM</span> which allows an alarm. Such events have a <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">DTSTART</span> which sets a starting time, and a <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">DTEND</span> which sets an ending time. If the calendar event is recurring, <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">DTSTART</span> sets up the start of the first event.</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">VTODO</span> explains a to-do item, i.e., an action-item or assignment. Not all calendar applications recognize <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">VTODO</span> items. In particular, Outlook does not export Tasks as <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">VTODO</span> items, and ignores <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">VTODO</span> items in imported calendars.<sup id="cite_ref-14" class="reference"><a href="#cite_note-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">VJOURNAL</span> is a journal entry. They attach descriptive text to a particular calendar date, may be used to record a daily record of activities or accomplishments, or describe progress with a related to-do entry. A <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">VJOURNAL</span> calendar component does not take up time on a calendar, so it has no effect on free or busy time (just like <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">TRANSPARENT</span> entries). In practice, few programs support <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">VJOURNAL</span> entries.</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">VFREEBUSY</span> is a request for free/busy time, is a response to a request, or is a published set of busy time.<sup class="noprint Inline-Template" style="margin-left:0.1em; white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Please_clarify" title="Wikipedia:Please clarify"><span title="The text near this tag may need clarification or removal of jargon. (December 2008)">clarification needed</span></a></i>]</sup></li> <li>Other component types include <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">VAVAILABILITY</span>, <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">VTIMEZONE</span> (time zones) and <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">VALARM</span> (alarms). Some components can include other components (<link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">VALARM</span> is often included in other components). Some components are often defined to support other components defined after them (<link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">VTIMEZONE</span> is often used this way).<sup class="noprint Inline-Template" style="margin-left:0.1em; white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Please_clarify" title="Wikipedia:Please clarify"><span title="The text near this tag may need clarification or removal of jargon. (December 2008)">clarification needed</span></a></i>]</sup></li></ul> <p>iCalendar is meant to "provide the definition of a common format for openly exchanging calendaring and scheduling information across the Internet". While the features most often used by users are widely supported by iCalendar, some more advanced capabilities have problems. For example, most vendors do not support Journals (<link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">VJOURNAL</span>). <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">VTODO</span>s have had conversion problems as well.<sup id="cite_ref-15" class="reference"><a href="#cite_note-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> </p><p>iCalendar's calendar is also not compatible with some non-<a href="/wiki/Gregorian_calendar" title="Gregorian calendar">Gregorian</a> calendars such as the <a href="/wiki/Lunar_calendar" title="Lunar calendar">lunar calendars</a> used in <a href="/wiki/Israel" title="Israel">Israel</a> and <a href="/wiki/Saudi_Arabia" title="Saudi Arabia">Saudi Arabia</a>. Although there exist one-to-one mappings between Gregorian and many other calendar scales, the lack of defined <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">CALSCALE</span> values for those calendars and limitations in various date fields can make native support impossible. For example the <a href="/wiki/Hebrew_calendar" title="Hebrew calendar">Hebrew calendar</a> year may contain either 12 or 13 months, and the <a href="/wiki/Japanese_era_name" title="Japanese era name">Japanese</a> Emperor-based calendar scale contains many eras. </p> <div class="mw-heading mw-heading2"><h2 id="Extensions">Extensions</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=ICalendar&action=edit&section=3" title="Edit section: Extensions"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>vCalendar and iCalendar support private <a href="/wiki/Software_extensions" class="mw-redirect" title="Software extensions">software extensions</a>, with a "X-" prefix, a number of which are in common usage. </p><p>Some of these include: </p> <ul><li><code>X-RECURRENCE-ID</code>: vCalendar 1.0 extension which mimics the iCalendar 2.0 RECURRENCE-ID (Nokia S60 3rd Edition)</li> <li><code>X-EPOCAGENDAENTRYTYPE</code>: defines the client calendar type</li> <li><code>X-FUNAMBOL-AALARMOPTIONS</code></li> <li><code>X-FUNAMBOL-ALLDAY</code>: All Day event flag</li> <li><code>X-MICROSOFT-CDO-ALLDAYEVENT</code>: Microsoft Outlook all day event flag</li> <li><code><a rel="nofollow" class="external text" href="https://learn.microsoft.com/en-us/openspecs/exchange_server_protocols/ms-oxcical/cd68eae7-ed65-4dd3-8ea7-ad585c76c736">X-MICROSOFT-CDO-BUSYSTATUS</a></code>: Microsoft Outlook status information</li> <li><code><a rel="nofollow" class="external text" href="https://learn.microsoft.com/en-us/openspecs/exchange_server_protocols/ms-oxcical/df1c7988-9908-4ee6-95b0-fcd180b02b44">X-MICROSOFT-CDO-INTENDEDSTATUS</a></code></li> <li><code>X-WR-CALNAME</code>: The display name of the calendar</li> <li><code>X-WR-CALDESC</code>: A description of the calendar</li> <li><code>X-WR-RELCALID</code>: A globally unique identifier for the calendar<sup id="cite_ref-16" class="reference"><a href="#cite_note-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup></li> <li><code>X-WR-TIMEZONE</code></li> <li><code>X-PUBLISHED-TTL</code>: Recommended update interval for subscription to the calendar</li> <li><code>X-ALT-DESC</code>: Used to include HTML markup in an event's description. Standard DESCRIPTION tag should contain non-HTML version.</li> <li><code>X-FMTTYPE</code>, <code>X-FILEDATE</code>, <code>X-NAME</code>, <code>X-CN</code>, <code>X-STATUS</code>, <code>X-ROLE</code>, <code>X-SENTBY</code>, <code>X-SYMBIAN-DTSTAMP</code>, <code>X-METHOD</code>, <code>X-RECURRENCE-ID</code>, <code>X-EPOCALARM</code>, <code>X-SYMBIAN-LUID</code>, <code>X-EPOCAGENDAENTRYTYPE</code><sup id="cite_ref-17" class="reference"><a href="#cite_note-17"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup></li></ul> <div class="mw-heading mw-heading2"><h2 id="List_of_components,_properties,_and_parameters"><span id="List_of_components.2C_properties.2C_and_parameters"></span>List of components, properties, and parameters</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=ICalendar&action=edit&section=4" title="Edit section: List of components, properties, and parameters"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <table class="wikitable sortable mw-collapsible"> <caption> </caption> <tbody><tr> <th>Name </th> <th>Kind</th> <th>RFC section (RFC 5545<sup id="cite_ref-:0_1-1" class="reference"><a href="#cite_note-:0-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup class="reference nowrap"><span title="Pages: 155–159, section 8.3">: 155–159, section 8.3 </span></sup> by default)</th> <th>MS-OXCICAL section 2.1.3<sup id="cite_ref-:1_18-0" class="reference"><a href="#cite_note-:1-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> subsections </th></tr> <tr> <td>VCALENDAR </td> <td>Component </td> <td>3.4. iCalendar Object </td> <td>1.1 </td></tr> <tr> <td>VEVENT</td> <td>Component</td> <td>3.6.1. Event Component </td> <td>1.1.20 </td></tr> <tr> <td>VTODO</td> <td>Component</td> <td>3.6.2. To-Do Component </td> <td> </td></tr> <tr> <td>VJOURNAL</td> <td>Component</td> <td>3.6.3. Journal Component </td> <td> </td></tr> <tr> <td>VFREEBUSY </td> <td>Component </td> <td>3.6.4. Free/Busy Component </td> <td> </td></tr> <tr> <td>VTIMEZONE </td> <td>Component </td> <td>3.6.5. Time Zone Component </td> <td> </td></tr> <tr> <td>STANDARD </td> <td>Component </td> <td>3.6.5. Time Zone Component </td> <td>1.1.19.2 </td></tr> <tr> <td>DAYLIGHT </td> <td>Component </td> <td>3.6.5. Time Zone Component </td> <td>1.1.19.3 </td></tr> <tr> <td>VALARM </td> <td>Component </td> <td>3.6.6. Alarm Component </td> <td> </td></tr> <tr> <td>VAVAILABILITY </td> <td>Component </td> <td>RFC 7953 section 3.1. VAVAILABILITY Component </td> <td> </td></tr> <tr> <td>AVAILABLE </td> <td>Component </td> <td>RFC 7953 section 3.1. VAVAILABILITY Component </td> <td> </td></tr> <tr> <td>PARTICIPANT </td> <td>Component </td> <td>RFC 9073 section 7.1. Participant </td> <td> </td></tr> <tr> <td>VLOCATION </td> <td>Component </td> <td>RFC 9073 section 7.2. Location </td> <td> </td></tr> <tr> <td>VRESOURCE </td> <td>Component </td> <td>RFC 9073 section 7.3. Resource </td> <td> </td></tr> <tr> <td>CALSCALE </td> <td>Property</td> <td>3.7.1. Calendar Scale</td> <td> </td></tr> <tr> <td>METHOD </td> <td>Property</td> <td>3.7.2. Method</td> <td>1.1.1 </td></tr> <tr> <td>PRODID </td> <td>Property</td> <td>3.7.3. Product Identifier</td> <td>1.1.2 </td></tr> <tr> <td>VERSION </td> <td>Property</td> <td>3.7.4. Version</td> <td>1.1.3 </td></tr> <tr> <td>X-CALEND </td> <td>Property </td> <td> </td> <td>1.1.4 </td></tr> <tr> <td>X-CALSTART </td> <td>Property </td> <td> </td> <td>1.1.5 </td></tr> <tr> <td>X-CLIPEND </td> <td>Property </td> <td> </td> <td>1.1.6 </td></tr> <tr> <td>X-CLIPSTART </td> <td>Property </td> <td> </td> <td>1.1.7 </td></tr> <tr> <td>X-MICROSOFT-CALSCALE </td> <td>Property </td> <td> </td> <td>1.1.8 </td></tr> <tr> <td>X-MS-OLK-FORCEINSPECTOROPEN </td> <td>Property </td> <td> </td> <td>1.1.9 </td></tr> <tr> <td>X-MS-WKHRDAYS </td> <td>Property </td> <td> </td> <td>1.1.10 </td></tr> <tr> <td>X-MS-WKHREND </td> <td>Property </td> <td> </td> <td>1.1.11 </td></tr> <tr> <td>X-MS-WKHRSTART </td> <td>Property </td> <td> </td> <td>1.1.12 </td></tr> <tr> <td>X-OWNER </td> <td>Property </td> <td> </td> <td>1.1.13 </td></tr> <tr> <td>X-PRIMARY-CALENDAR </td> <td>Property </td> <td> </td> <td>1.1.14 </td></tr> <tr> <td>X-PUBLISHED-TTL </td> <td>Property </td> <td> </td> <td>1.1.15 </td></tr> <tr> <td>X-WR-CALDESC </td> <td>Property</td> <td></td> <td>1.1.16 </td></tr> <tr> <td>X-WR-CALNAME </td> <td>Property</td> <td></td> <td>1.1.17 </td></tr> <tr> <td>X-WR-RELCALID </td> <td>Property</td> <td></td> <td>1.1.18 </td></tr> <tr> <td>ATTACH </td> <td>Property</td> <td>3.8.1.1. Attachment</td> <td>1.1.20.1 </td></tr> <tr> <td>CATEGORIES </td> <td>Property</td> <td>3.8.1.2. Categories, RFC 7986 section 5.6. CATEGORIES Property</td> <td>1.1.20.3 </td></tr> <tr> <td>CLASS </td> <td>Property</td> <td>3.8.1.3. Classification</td> <td>1.1.20.4 </td></tr> <tr> <td>COMMENT </td> <td>Property</td> <td>3.8.1.4. Comment</td> <td>1.1.20.5 </td></tr> <tr> <td>DESCRIPTION </td> <td>Property</td> <td>3.8.1.5. Description, RFC 7986 section 5.2. DESCRIPTION Property</td> <td>1.1.20.11, 1.1.20.62.3 </td></tr> <tr> <td>GEO </td> <td>Property</td> <td>3.8.1.6. Geographic Position</td> <td> </td></tr> <tr> <td>LOCATION </td> <td>Property</td> <td>3.8.1.7. Location</td> <td>1.1.20.15 </td></tr> <tr> <td>PERCENT-COMPLETE </td> <td>Property</td> <td>3.8.1.8. Percent Complete</td> <td> </td></tr> <tr> <td>PRIORITY </td> <td>Property</td> <td>3.8.1.9. Priority</td> <td>1.1.20.17 </td></tr> <tr> <td>RESOURCES </td> <td>Property</td> <td>3.8.1.10. Resources</td> <td>1.1.20.21 </td></tr> <tr> <td>STATUS </td> <td>Property</td> <td>3.8.1.11. Status</td> <td>1.1.20.23 </td></tr> <tr> <td>SUMMARY </td> <td>Property</td> <td>3.8.1.12. Summary</td> <td>1.1.20.24 </td></tr> <tr> <td>COMPLETED </td> <td>Property</td> <td>3.8.2.1. Date-Time Completed</td> <td> </td></tr> <tr> <td>DTEND </td> <td>Property</td> <td>3.8.2.2. Date-Time End</td> <td>1.1.20.8 </td></tr> <tr> <td>DUE </td> <td>Property</td> <td>3.8.2.3. Date-Time Due</td> <td> </td></tr> <tr> <td>DTSTART </td> <td>Property</td> <td>3.8.2.4. Date-Time Start</td> <td>1.1.19.2.1, 1.1.19.3.1, 1.1.20.10 </td></tr> <tr> <td>DURATION </td> <td>Property</td> <td>3.8.2.5. Duration</td> <td>1.1.20.12 </td></tr> <tr> <td>FREEBUSY </td> <td>Property</td> <td>3.8.2.6. Free/Busy Time</td> <td> </td></tr> <tr> <td>TRANSP </td> <td>Property</td> <td>3.8.2.7. Time Transparency</td> <td>1.1.20.25 </td></tr> <tr> <td>TZID </td> <td>Property</td> <td>3.8.3.1. Time Zone Identifier</td> <td>1.1.19.1 </td></tr> <tr> <td>TZNAME </td> <td>Property</td> <td>3.8.3.2. Time Zone Name</td> <td>1.1.19.2.3, 1.1.19.3.3 </td></tr> <tr> <td>TZOFFSETFROM </td> <td>Property</td> <td>3.8.3.3. Time Zone Offset From</td> <td>1.1.19.2.4, 1.1.19.3.4 </td></tr> <tr> <td>TZOFFSETTO </td> <td>Property</td> <td>3.8.3.4. Time Zone Offset To</td> <td>1.1.19.2.5, 1.1.19.3.5 </td></tr> <tr> <td>TZURL </td> <td>Property</td> <td>3.8.3.5. Time Zone URL</td> <td> </td></tr> <tr> <td>ATTENDEE </td> <td>Property</td> <td>3.8.4.1. Attendee</td> <td>1.1.20.2 </td></tr> <tr> <td>CONTACT </td> <td>Property</td> <td>3.8.4.2. Contact</td> <td>1.1.20.6 </td></tr> <tr> <td>ORGANIZER </td> <td>Property</td> <td>3.8.4.3. Organizer</td> <td>1.1.20.16 </td></tr> <tr> <td>RECURRENCE-ID </td> <td>Property</td> <td>3.8.4.4. Recurrence ID</td> <td>1.1.20.20 </td></tr> <tr> <td>RELATED-TO </td> <td>Property</td> <td>3.8.4.5. Related To, RFC 9253 section 9.1. RELATED-TO</td> <td> </td></tr> <tr> <td>URL </td> <td>Property</td> <td>3.8.4.6. Uniform Resource Locator, RFC 7986 section 5.5. URL Property</td> <td> </td></tr> <tr> <td>UID </td> <td>Property</td> <td>3.8.4.7. Unique Identifier, RFC 7986 section 5.3. UID Property</td> <td>1.1.20.26 </td></tr> <tr> <td>EXDATE </td> <td>Property</td> <td>3.8.5.1. Exception Date-Times</td> <td>1.1.20.13 </td></tr> <tr> <td>RDATE </td> <td>Property</td> <td>3.8.5.2. Recurrence Date-Times</td> <td>1.1.20.18 </td></tr> <tr> <td>RRULE </td> <td>Property</td> <td>3.8.5.3. Recurrence Rule</td> <td>1.1.19.2.2, 1.1.19.3.2, 1.1.20.19 </td></tr> <tr> <td>ACTION </td> <td>Property</td> <td>3.8.6.1. Action</td> <td>1.1.20.62.2 </td></tr> <tr> <td>REPEAT </td> <td>Property</td> <td>3.8.6.2. Repeat Count</td> <td> </td></tr> <tr> <td>TRIGGER </td> <td>Property</td> <td>3.8.6.3. Trigger</td> <td>1.1.20.62.1 </td></tr> <tr> <td>CREATED </td> <td>Property</td> <td>3.8.7.1. Date-Time Created</td> <td>1.1.20.7 </td></tr> <tr> <td>DTSTAMP </td> <td>Property</td> <td>3.8.7.2. Date-Time Stamp</td> <td>1.1.20.9 </td></tr> <tr> <td>LAST-MODIFIED </td> <td>Property</td> <td>3.8.7.3. Last Modified, RFC 7986 section 5.4. LAST-MODIFIED Property</td> <td>1.1.20.14 </td></tr> <tr> <td>SEQUENCE </td> <td>Property</td> <td>3.8.7.4. Sequence Number</td> <td>1.1.20.22 </td></tr> <tr> <td>REQUEST-STATUS </td> <td>Property</td> <td>3.8.8.3. Request Status</td> <td> </td></tr> <tr> <td>X-ALT-DESC </td> <td>Property </td> <td> </td> <td>1.1.20.27 </td></tr> <tr> <td>X-MICROSOFT-CDO-ALLDAYEVENT </td> <td>Property </td> <td> </td> <td>1.1.20.28 </td></tr> <tr> <td>X-MICROSOFT-CDO-APPT-SEQUENCE</td> <td>Property</td> <td></td> <td>1.1.20.29 </td></tr> <tr> <td>X-MICROSOFT-CDO-ATTENDEE-CRITICAL-CHANGE</td> <td>Property</td> <td></td> <td>1.1.20.30 </td></tr> <tr> <td>X-MICROSOFT-CDO-BUSYSTATUS</td> <td>Property</td> <td></td> <td>1.1.20.31 </td></tr> <tr> <td>X-MICROSOFT-CDO-IMPORTANCE</td> <td>Property</td> <td></td> <td>1.1.20.32 </td></tr> <tr> <td>X-MICROSOFT-CDO-INSTTYPE</td> <td>Property</td> <td></td> <td>1.1.20.33 </td></tr> <tr> <td>X-MICROSOFT-CDO-INTENDEDSTATUS</td> <td>Property</td> <td></td> <td>1.1.20.34 </td></tr> <tr> <td>X-MICROSOFT-CDO-OWNERAPPTID</td> <td>Property</td> <td></td> <td>1.1.20.35 </td></tr> <tr> <td>X-MICROSOFT-CDO-OWNER-CRITICAL-CHANGE</td> <td>Property</td> <td></td> <td>1.1.20.36 </td></tr> <tr> <td>X-MICROSOFT-CDO-REPLYTIME</td> <td>Property</td> <td></td> <td>1.1.20.37 </td></tr> <tr> <td>X-MICROSOFT-DISALLOW-COUNTER</td> <td>Property</td> <td></td> <td>1.1.20.38 </td></tr> <tr> <td>X-MICROSOFT-EXDATE</td> <td>Property</td> <td></td> <td>1.1.20.39 </td></tr> <tr> <td>X-MICROSOFT-ISDRAFT</td> <td>Property</td> <td></td> <td>1.1.20.40 </td></tr> <tr> <td>X-MICROSOFT-MSNCALENDAR-ALLDAYEVENT</td> <td>Property</td> <td></td> <td>1.1.20.41 </td></tr> <tr> <td>X-MICROSOFT-MSNCALENDAR-BUSYSTATUS</td> <td>Property</td> <td></td> <td>1.1.20.42 </td></tr> <tr> <td>X-MICROSOFT-MSNCALENDAR-IMPORTANCE</td> <td>Property</td> <td></td> <td>1.1.20.43 </td></tr> <tr> <td>X-MICROSOFT-MSNCALENDAR-INTENDEDSTATUS</td> <td>Property</td> <td></td> <td>1.1.20.44 </td></tr> <tr> <td>X-MICROSOFT-RRULE</td> <td>Property</td> <td></td> <td>1.1.20.45 </td></tr> <tr> <td>X-MS-OLK-ALLOWEXTERNCHECK</td> <td>Property</td> <td></td> <td>1.1.20.46 </td></tr> <tr> <td>X-MS-OLK-APPTLASTSEQUENCE</td> <td>Property</td> <td></td> <td>1.1.20.47 </td></tr> <tr> <td>X-MS-OLK-APPTSEQTIME</td> <td>Property</td> <td></td> <td>1.1.20.48 </td></tr> <tr> <td>X-MS-OLK-AUTOFILLLOCATION</td> <td>Property</td> <td></td> <td>1.1.20.49 </td></tr> <tr> <td>X-MS-OLK-AUTOSTARTCHECK</td> <td>Property</td> <td></td> <td>1.1.20.50 </td></tr> <tr> <td>X-MS-OLK-COLLABORATEDOC</td> <td>Property</td> <td></td> <td>1.1.20.51 </td></tr> <tr> <td>X-MS-OLK-CONFCHECK</td> <td>Property</td> <td></td> <td>1.1.20.52 </td></tr> <tr> <td>X-MS-OLK-CONFTYPE</td> <td>Property</td> <td></td> <td>1.1.20.53 </td></tr> <tr> <td>X-MS-OLK-DIRECTORY</td> <td>Property</td> <td></td> <td>1.1.20.54 </td></tr> <tr> <td>X-MS-OLK-MWSURL</td> <td>Property</td> <td></td> <td>1.1.20.55 </td></tr> <tr> <td>X-MS-OLK-NETSHOWURL</td> <td>Property</td> <td></td> <td>1.1.20.56 </td></tr> <tr> <td>X-MS-OLK-ONLINEPASSWORD</td> <td>Property</td> <td></td> <td>1.1.20.57 </td></tr> <tr> <td>X-MS-OLK-ORGALIAS</td> <td>Property</td> <td></td> <td>1.1.20.58 </td></tr> <tr> <td>X-MS-OLK-SENDER</td> <td>Property</td> <td></td> <td>1.1.20.61 </td></tr> <tr> <td>BUSYTYPE </td> <td>Property </td> <td>RFC 7953 section 3.2. Busy Time Type </td> <td> </td></tr> <tr> <td>NAME </td> <td>Property </td> <td>RFC 7986 section 5.1. NAME Property </td> <td> </td></tr> <tr> <td>REFRESH-INTERVAL </td> <td>Property </td> <td>RFC 7986 section 5.7. REFRESH-INTERVAL Property </td> <td> </td></tr> <tr> <td>SOURCE </td> <td>Property </td> <td>RFC 7986 section 5.8. SOURCE Property </td> <td> </td></tr> <tr> <td>COLOR </td> <td>Property </td> <td>RFC 7986 section 5.9. COLOR Property </td> <td> </td></tr> <tr> <td>IMAGE </td> <td>Property </td> <td>RFC 7986 section 5.10. IMAGE Property </td> <td> </td></tr> <tr> <td>CONFERENCE </td> <td>Property </td> <td>RFC 7986 section 5.11. CONFERENCE Property </td> <td> </td></tr> <tr> <td>CALENDAR-ADDRESS </td> <td>Property </td> <td>RFC 9073 section 6.4. Calendar Address </td> <td> </td></tr> <tr> <td>LOCATION-TYPE </td> <td>Property </td> <td>RFC 9073 section 6.1. Location Type </td> <td> </td></tr> <tr> <td>PARTICIPANT-TYPE </td> <td>Property </td> <td>RFC 9073 section 6.2. Participant Type </td> <td> </td></tr> <tr> <td>RESOURCE-TYPE </td> <td>Property </td> <td>RFC 9073 section 6.3. Resource Type </td> <td> </td></tr> <tr> <td>STRUCTURED-DATA </td> <td>Property </td> <td>RFC 9073 section 6.6. Structured-Data </td> <td> </td></tr> <tr> <td>STYLED-DESCRIPTION </td> <td>Property </td> <td>RFC 9073 section 6.5. Styled-Description </td> <td> </td></tr> <tr> <td>ACKNOWLEDGED </td> <td>Property </td> <td>RFC 9074 section 6.1. Acknowledged Property </td> <td> </td></tr> <tr> <td>PROXIMITY </td> <td>Property </td> <td>RFC 9074 section 8.1. Proximity Property </td> <td> </td></tr> <tr> <td>CONCEPT </td> <td>Property </td> <td>RFC 9253 section 8.1. Concept </td> <td> </td></tr> <tr> <td>LINK </td> <td>Property </td> <td>RFC 9253 section 8.2. Link </td> <td> </td></tr> <tr> <td>REFID </td> <td>Property </td> <td>RFC 9253 section 8.3. Refid </td> <td> </td></tr> <tr> <td>ALTREP</td> <td>Parameter</td> <td>3.2.1. Alternate Text Representation </td> <td>1.1.20.15.1 </td></tr> <tr> <td>CN</td> <td>Parameter</td> <td>3.2.2. Common Name </td> <td>1.1.13.1, 1.1.20.2.1, 1.1.20.16.1, 1.1.20.61.1 </td></tr> <tr> <td>CUTYPE</td> <td>Parameter</td> <td>3.2.3. Calendar User Type </td> <td>1.1.20.2.2 </td></tr> <tr> <td>DELEGATED-FROM</td> <td>Parameter</td> <td>3.2.4. Delegators </td> <td> </td></tr> <tr> <td>DELEGATED-TO</td> <td>Parameter</td> <td>3.2.5. Delegatees </td> <td> </td></tr> <tr> <td>DIR</td> <td>Parameter</td> <td>3.2.6. Directory Entry Reference </td> <td> </td></tr> <tr> <td>ENCODING</td> <td>Parameter</td> <td>3.2.7. Inline Encoding </td> <td>1.1.20.1.1 </td></tr> <tr> <td>FMTTYPE</td> <td>Parameter</td> <td>3.2.8. Format Type </td> <td>1.1.20.1.2, 1.1.20.27.1 </td></tr> <tr> <td>FBTYPE</td> <td>Parameter</td> <td>3.2.9. Free/Busy Time Type </td> <td> </td></tr> <tr> <td>LANGUAGE</td> <td>Parameter</td> <td>3.2.10. Language </td> <td>1.1.20.11.1, 1.1.20.15.2, 1.1.20.24.1 </td></tr> <tr> <td>MEMBER</td> <td>Parameter</td> <td>3.2.11. Group or List Membership </td> <td> </td></tr> <tr> <td>PARTSTAT</td> <td>Parameter</td> <td>3.2.12. Participation Status </td> <td>1.1.20.2.3 </td></tr> <tr> <td>RANGE</td> <td>Parameter</td> <td>3.2.13. Recurrence Identifier Range </td> <td> </td></tr> <tr> <td>RELATED</td> <td>Parameter</td> <td>3.2.14. Alarm Trigger Relationship </td> <td> </td></tr> <tr> <td>RELTYPE</td> <td>Parameter</td> <td>3.2.15. Relationship Type, RFC 9074 section 7.1. Relationship Type Property Parameter, RFC 9253 sections 4 and 5 </td> <td> </td></tr> <tr> <td>ROLE</td> <td>Parameter</td> <td>3.2.16. Participation Role </td> <td>1.1.20.2.4 </td></tr> <tr> <td>RSVP</td> <td>Parameter</td> <td>3.2.17. RSVP Expectation </td> <td>1.1.20.2.5 </td></tr> <tr> <td>SENT-BY</td> <td>Parameter</td> <td>3.2.18. Sent By </td> <td> </td></tr> <tr> <td>TZID</td> <td>Parameter</td> <td>3.2.19. Time Zone Identifier </td> <td>1.1.4.1, 1.1.5.1, 1.1.6.1, 1.1.7.1, 1.1.11.1, 1.1.12.1, 1.1.20.8.1, 1.1.20.9.1, 1.1.20.10.1, 1.1.20.13.1, 1.1.20.18.1, 1.1.20.20.1, 1.1.20.48.1 </td></tr> <tr> <td>VALUE</td> <td>Parameter</td> <td>3.2.20. Value Data Types </td> <td>1.1.20.1.3, 1.1.20.8.2, 1.1.20.10.2, 1.1.20.13.2, 1.1.20.18.2, 1.1.20.20.2, 1.1.20.39.1, 1.1.20.45.1 </td></tr> <tr> <td>X-FILENAME </td> <td>Parameter </td> <td> </td> <td>1.1.20.1.4 </td></tr> <tr> <td>X-MS-OLK-RESPTIME </td> <td>Parameter </td> <td> </td> <td>1.1.20.2.6 </td></tr> <tr> <td>X-MICROSOFT-ISLEAPMONTH </td> <td>Parameter </td> <td> </td> <td>1.1.20.45.2 </td></tr> <tr> <td>DISPLAY </td> <td>Parameter </td> <td>RFC 7986 section 6.1. DISPLAY Property Parameter </td> <td> </td></tr> <tr> <td>EMAIL </td> <td>Parameter </td> <td>RFC 7986 section 6.2. EMAIL Property Parameter </td> <td> </td></tr> <tr> <td>FEATURE </td> <td>Parameter </td> <td>RFC 7986 section 6.3. FEATURE Property Parameter </td> <td> </td></tr> <tr> <td>LABEL </td> <td>Parameter </td> <td>RFC 7986 section 6.4. LABEL Property Parameter </td> <td> </td></tr> <tr> <td>ORDER </td> <td>Parameter </td> <td>RFC 9073 section 5.1. Order </td> <td> </td></tr> <tr> <td>SCHEMA </td> <td>Parameter </td> <td>RFC 9073 section 5.2. Schema </td> <td> </td></tr> <tr> <td>DERIVED </td> <td>Parameter </td> <td>RFC 9073 section 5.3. Derived </td> <td> </td></tr> <tr> <td>GAP </td> <td>Parameter </td> <td>RFC 9253 section 6.2. Gap </td> <td> </td></tr> <tr> <td>LINKREL </td> <td>Parameter </td> <td>RFC 9253 section 6.1. Link Relation </td> <td> </td></tr></tbody></table> <div class="mw-heading mw-heading2"><h2 id="Other_representations">Other representations</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=ICalendar&action=edit&section=5" title="Edit section: Other representations"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><a href="/wiki/XCal" title="XCal">xCal</a> is an <a href="/wiki/XML" title="XML">XML</a> representation of iCalendar data, as defined in <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><a href="/wiki/RFC_(identifier)" class="mw-redirect" title="RFC (identifier)">RFC</a> <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc6321">6321</a>. </p><p>jCal is a <a href="/wiki/JSON" title="JSON">JSON</a> representation of iCalendar data, as defined in <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><a href="/wiki/RFC_(identifier)" class="mw-redirect" title="RFC (identifier)">RFC</a> <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc7265">7265</a>. </p><p><a href="/wiki/HCalendar" title="HCalendar">hCalendar</a> is an <a href="/wiki/(X)HTML" class="mw-redirect" title="(X)HTML">(x)HTML</a> representation of a subset of iCalendar data using <a href="/wiki/Microformat" title="Microformat">microformats</a>. </p><p>hEvent is an HTML representation of a subset of iCalendar data using <a href="/wiki/Microformat" title="Microformat">microformats</a> addressing some accessibility concerns with the hCalendar format. </p> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=ICalendar&action=edit&section=6" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/CalDAV" title="CalDAV">CalDAV</a> – Internet standard for sharing calendar data</li> <li><a href="/wiki/VCard" title="VCard">vCard</a> – File format standard for electronic business cards</li></ul> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=ICalendar&action=edit&section=7" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist"> <div class="mw-references-wrap mw-references-columns"><ol class="references"> <li id="cite_note-:0-1"><span class="mw-cite-backlink">^ <a href="#cite_ref-:0_1-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-:0_1-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFDesruisseaux2009" class="citation cs1">Desruisseaux, Bernard, ed. (September 2009). <a rel="nofollow" class="external text" href="https://icalendar.org/RFC-Specifications/iCalendar-RFC-5545/"><i>Internet Calendaring and Scheduling Core Object Specification (iCalendar)</i></a>. <a href="/wiki/Internet_Engineering_Task_Force" title="Internet Engineering Task Force">Internet Engineering Task Force</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.17487%2FRFC5545">10.17487/RFC5545</a></span>. <a href="/wiki/Request_for_Comments" title="Request for Comments">RFC</a> <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc5545">5545</a><span class="reference-accessdate">. Retrieved <span class="nowrap">2018-12-07</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Internet+Calendaring+and+Scheduling+Core+Object+Specification+%28iCalendar%29&rft.pub=Internet+Engineering+Task+Force&rft.date=2009-09&rft_id=info%3Adoi%2F10.17487%2FRFC5545&rft_id=https%3A%2F%2Ficalendar.org%2FRFC-Specifications%2FiCalendar-RFC-5545%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AICalendar" class="Z3988"></span></span> </li> <li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.ibm.com/developerworks/lotus/library/notes85-icalendar/index.html">"IBM Lotus Notes 8.5 iCalendar: Interoperability, implementation, and application"</a>. IBM DeveloperWorks<span class="reference-accessdate">. Retrieved <span class="nowrap">2015-04-05</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=IBM+Lotus+Notes+8.5+iCalendar%3A+Interoperability%2C+implementation%2C+and+application&rft.pub=IBM+DeveloperWorks&rft_id=http%3A%2F%2Fwww.ibm.com%2Fdeveloperworks%2Flotus%2Flibrary%2Fnotes85-icalendar%2Findex.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AICalendar" class="Z3988"></span></span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://icalendar.org/">"iCalendar.org"</a>. Z Content<span class="reference-accessdate">. Retrieved <span class="nowrap">2018-03-28</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=iCalendar.org&rft.pub=Z+Content&rft_id=https%3A%2F%2Ficalendar.org%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AICalendar" class="Z3988"></span></span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20160321023312/https://www.imc.org/pdi/vcal-10.txt">"vCalendar: The Electronic Calendaring and Scheduling Exchange Format, Version 1.0"</a>. <a href="/wiki/Internet_Mail_Consortium" title="Internet Mail Consortium">Internet Mail Consortium</a>. 1996-09-18. Archived from <a rel="nofollow" class="external text" href="http://www.imc.org/pdi/vcal-10.txt">the original</a> on 2016-03-21<span class="reference-accessdate">. Retrieved <span class="nowrap">2018-03-28</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=vCalendar%3A+The+Electronic+Calendaring+and+Scheduling+Exchange+Format%2C+Version+1.0&rft.pub=Internet+Mail+Consortium&rft.date=1996-09-18&rft_id=http%3A%2F%2Fwww.imc.org%2Fpdi%2Fvcal-10.txt&rfr_id=info%3Asid%2Fen.wikipedia.org%3AICalendar" class="Z3988"></span></span> </li> <li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20150906130553/http://www.imc.org/pdi/">"vCalendar: The Basis for Cross-Platform Scheduling"</a>. <a href="/wiki/Internet_Mail_Consortium" title="Internet Mail Consortium">Internet Mail Consortium</a>. 2006-11-26. Archived from <a rel="nofollow" class="external text" href="https://www.imc.org/pdi/">the original</a> on 2015-09-06<span class="reference-accessdate">. Retrieved <span class="nowrap">2016-02-28</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=vCalendar%3A+The+Basis+for+Cross-Platform+Scheduling&rft.pub=Internet+Mail+Consortium&rft.date=2006-11-26&rft_id=https%3A%2F%2Fwww.imc.org%2Fpdi%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AICalendar" class="Z3988"></span></span> </li> <li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://datatracker.ietf.org/wg/calsify/charter/">"Calendaring and Scheduling Standards Simplification (calsify)"</a>. <a href="/wiki/IETF" class="mw-redirect" title="IETF">IETF</a><span class="reference-accessdate">. Retrieved <span class="nowrap">2015-04-05</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Calendaring+and+Scheduling+Standards+Simplification+%28calsify%29&rft.pub=IETF&rft_id=https%3A%2F%2Fdatatracker.ietf.org%2Fwg%2Fcalsify%2Fcharter%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AICalendar" class="Z3988"></span></span> </li> <li id="cite_note-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-7">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFLear2010" class="citation web cs1">Lear, Eliot (2010-12-10). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20121209115511/http://lists.osafoundation.org/pipermail/ietf-calsify/2010-December/002272.html">"the end of calsify working group– not the end of the mailing list"</a>. <i>ietf-calsify mailing list</i>. Archived from <a rel="nofollow" class="external text" href="http://lists.osafoundation.org/pipermail/ietf-calsify/2010-December/002272.html">the original</a> on 2012-12-09<span class="reference-accessdate">. Retrieved <span class="nowrap">2015-04-05</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=ietf-calsify+mailing+list&rft.atitle=the+end+of+calsify+working+group%E2%80%93+not+the+end+of+the+mailing+list&rft.date=2010-12-10&rft.aulast=Lear&rft.aufirst=Eliot&rft_id=http%3A%2F%2Flists.osafoundation.org%2Fpipermail%2Fietf-calsify%2F2010-December%2F002272.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AICalendar" class="Z3988"></span></span> </li> <li id="cite_note-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-8">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://datatracker.ietf.org/wg/calext/charter/">"Calendaring Extensions (calext)"</a>. <a href="/wiki/IETF" class="mw-redirect" title="IETF">IETF</a><span class="reference-accessdate">. Retrieved <span class="nowrap">2016-12-01</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Calendaring+Extensions+%28calext%29&rft.pub=IETF&rft_id=https%3A%2F%2Fdatatracker.ietf.org%2Fwg%2Fcalext%2Fcharter%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AICalendar" class="Z3988"></span></span> </li> <li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation cs1"><a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc5545#section-3.6">"Section 3.6 Calendar Components"</a>. <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc5545"><i>Internet Calendaring and Scheduling Core Object Specification (iCalendar)</i></a>. sec. 3.6. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.17487%2FRFC5545">10.17487/RFC5545</a></span>. <a href="/wiki/Request_for_Comments" title="Request for Comments">RFC</a> <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc5545">5545</a><span class="reference-accessdate">. Retrieved <span class="nowrap">1 July</span> 2020</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Section+3.6+Calendar+Components&rft.btitle=Internet+Calendaring+and+Scheduling+Core+Object+Specification+%28iCalendar%29&rft.pages=sec.-3.6&rft_id=info%3Adoi%2F10.17487%2FRFC5545&rft_id=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fhtml%2Frfc5545%26%23035%3Bsection-3.6&rfr_id=info%3Asid%2Fen.wikipedia.org%3AICalendar" class="Z3988"></span></span> </li> <li id="cite_note-10"><span class="mw-cite-backlink"><b><a href="#cite_ref-10">^</a></b></span> <span class="reference-text">From RFC 2445</span> </li> <li id="cite_note-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-11">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation cs1"><a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc7986#section-5.3">"UID Property"</a>. <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc7986"><i>iCalendar Property Extensions</i></a>. sec. 5.3. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.17487%2FRFC7986">10.17487/RFC7986</a></span>. <a href="/wiki/Request_for_Comments" title="Request for Comments">RFC</a> <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc7986">7986</a><span class="reference-accessdate">. Retrieved <span class="nowrap">3 October</span> 2022</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=UID+Property&rft.btitle=iCalendar+Property+Extensions&rft.pages=sec.-5.3&rft_id=info%3Adoi%2F10.17487%2FRFC7986&rft_id=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fhtml%2Frfc7986%26%23035%3Bsection-5.3&rfr_id=info%3Asid%2Fen.wikipedia.org%3AICalendar" class="Z3988"></span></span> </li> <li id="cite_note-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-12">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation cs1"><a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc5545#section-3.3.5">"Section 3.3.5 Date-Time"</a>. <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc5545"><i>Internet Calendaring and Scheduling Core Object Specification (iCalendar)</i></a>. sec. 3.3.5. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.17487%2FRFC5545">10.17487/RFC5545</a></span>. <a href="/wiki/Request_for_Comments" title="Request for Comments">RFC</a> <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc5545">5545</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Section+3.3.5+Date-Time&rft.btitle=Internet+Calendaring+and+Scheduling+Core+Object+Specification+%28iCalendar%29&rft.pages=sec.-3.3.5&rft_id=info%3Adoi%2F10.17487%2FRFC5545&rft_id=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fhtml%2Frfc5545%26%23035%3Bsection-3.3.5&rfr_id=info%3Asid%2Fen.wikipedia.org%3AICalendar" class="Z3988"></span></span> </li> <li id="cite_note-13"><span class="mw-cite-backlink"><b><a href="#cite_ref-13">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation cs1"><a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc5545#section-3.6.1">"Section 3.6.1 Event Components"</a>. <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc5545"><i>Internet Calendaring and Scheduling Core Object Specification (iCalendar)</i></a>. sec. 3.6.1. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.17487%2FRFC5545">10.17487/RFC5545</a></span>. <a href="/wiki/Request_for_Comments" title="Request for Comments">RFC</a> <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc5545">5545</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Section+3.6.1+Event+Components&rft.btitle=Internet+Calendaring+and+Scheduling+Core+Object+Specification+%28iCalendar%29&rft.pages=sec.-3.6.1&rft_id=info%3Adoi%2F10.17487%2FRFC5545&rft_id=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fhtml%2Frfc5545%26%23035%3Bsection-3.6.1&rfr_id=info%3Asid%2Fen.wikipedia.org%3AICalendar" class="Z3988"></span></span> </li> <li id="cite_note-14"><span class="mw-cite-backlink"><b><a href="#cite_ref-14">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://msdn.microsoft.com/en-us/library/ee624464%28v=exchg.80%29.aspx">"[RFC5546] Section 3.4 Methods for VTODO Components"</a>. <i>Microsoft Developer Network</i><span class="reference-accessdate">. Retrieved <span class="nowrap">7 August</span> 2015</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Microsoft+Developer+Network&rft.atitle=%5BRFC5546%5D+Section+3.4+Methods+for+VTODO+Components&rft_id=https%3A%2F%2Fmsdn.microsoft.com%2Fen-us%2Flibrary%2Fee624464%2528v%3Dexchg.80%2529.aspx&rfr_id=info%3Asid%2Fen.wikipedia.org%3AICalendar" class="Z3988"></span></span> </li> <li id="cite_note-15"><span class="mw-cite-backlink"><b><a href="#cite_ref-15">^</a></b></span> <span class="reference-text">CalConnect, 2004</span> </li> <li id="cite_note-16"><span class="mw-cite-backlink"><b><a href="#cite_ref-16">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://msdn.microsoft.com/en-us/library/ee179588(v=exchg.80).aspx">"[MS-OXCICAL]: Property: X-WR-RELCALID"</a>. <i>msdn.microsoft.com</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2016-02-23</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=msdn.microsoft.com&rft.atitle=%5BMS-OXCICAL%5D%3A+Property%3A+X-WR-RELCALID&rft_id=https%3A%2F%2Fmsdn.microsoft.com%2Fen-us%2Flibrary%2Fee179588%28v%3Dexchg.80%29.aspx&rfr_id=info%3Asid%2Fen.wikipedia.org%3AICalendar" class="Z3988"></span></span> </li> <li id="cite_note-17"><span class="mw-cite-backlink"><b><a href="#cite_ref-17">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://devlib.symbian.slions.net/s3/GUID-7811C33D-96D3-5001-B4D3-92BF44F39B2C.html">"iCal and vCal Properties"</a>. <i>Nokia Symbian^3 Developer's Library v1.1</i>. © <a href="/wiki/Nokia_Corporation" class="mw-redirect" title="Nokia Corporation">Nokia Corporation</a> 2011. October 8, 2009. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20210509022426/http://devlib.symbian.slions.net/s3/GUID-7811C33D-96D3-5001-B4D3-92BF44F39B2C.html">Archived</a> from the original on May 9, 2021<span class="reference-accessdate">. Retrieved <span class="nowrap">2023-11-17</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Nokia+Symbian%5E3+Developer%27s+Library+v1.1&rft.atitle=iCal+and+vCal+Properties&rft.date=2009-10-08&rft_id=http%3A%2F%2Fdevlib.symbian.slions.net%2Fs3%2FGUID-7811C33D-96D3-5001-B4D3-92BF44F39B2C.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AICalendar" class="Z3988"></span><span class="cs1-maint citation-comment"><code class="cs1-code">{{<a href="/wiki/Template:Cite_web" title="Template:Cite web">cite web</a>}}</code>: CS1 maint: others (<a href="/wiki/Category:CS1_maint:_others" title="Category:CS1 maint: others">link</a>)</span></span> </li> <li id="cite_note-:1-18"><span class="mw-cite-backlink"><b><a href="#cite_ref-:1_18-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://learn.microsoft.com/en-us/openspecs/exchange_server_protocols/ms-oxcical/74d3bf60-f30d-4fca-84d3-cfd04da8e627">"[MS-OXCICAL]: 2.1.3 Processing Rules"</a>. <i>learn.microsoft.com</i>. 2020-10-13. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20231116165430/https://learn.microsoft.com/en-us/openspecs/exchange_server_protocols/ms-oxcical/74d3bf60-f30d-4fca-84d3-cfd04da8e627">Archived</a> from the original on 2023-11-16<span class="reference-accessdate">. Retrieved <span class="nowrap">2023-11-16</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=learn.microsoft.com&rft.atitle=%5BMS-OXCICAL%5D%3A+2.1.3+Processing+Rules&rft.date=2020-10-13&rft_id=https%3A%2F%2Flearn.microsoft.com%2Fen-us%2Fopenspecs%2Fexchange_server_protocols%2Fms-oxcical%2F74d3bf60-f30d-4fca-84d3-cfd04da8e627&rfr_id=info%3Asid%2Fen.wikipedia.org%3AICalendar" class="Z3988"></span></span> </li> </ol></div></div> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=ICalendar&action=edit&section=8" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222">RFC <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc5545">5545</a> Internet Calendaring and Scheduling Core Object Specification (iCalendar) (replaces <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222">RFC <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc2445">2445</a>)</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222">RFC <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc5546">5546</a> iCalendar Transport-Independent Interoperability Protocol (iTIP) (replaces <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222">RFC <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc2446">2446</a>)</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222">RFC <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc6047">6047</a> iCalendar Message-Based Interoperability Protocol (iMIP) (replaces <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222">RFC <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc2447">2447</a>)</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222">RFC <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc6321">6321</a> xCal: The XML format for iCalendar (iCalendar XML Representation)</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222">RFC <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc6868">6868</a> update of the data formats for including certain characters, forbidden by the existing specification, in parameter values</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222">RFC <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc7265">7265</a> jCal: The JSON Format for iCalendar</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222">RFC <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc7953">7953</a> Calendar Availability</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222">RFC <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc7986">7986</a> New Properties for iCalendar (additional properties to the iCalendar specification)</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222">RFC <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc9073">9073</a> Event Publishing Extensions to iCalendar</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222">RFC <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc9074">9074</a> "VALARM" Extensions for iCalendar</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222">RFC <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc9253">9253</a> Support for iCalendar Relationships</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.calconnect.org/resources/introduction-internet-calendaring">"An Introduction to Internet Calendaring and Scheduling"</a>. <a href="/wiki/CalConnect" class="mw-redirect" title="CalConnect">CalConnect</a>. 2011-10-20.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=An+Introduction+to+Internet+Calendaring+and+Scheduling&rft.pub=CalConnect&rft.date=2011-10-20&rft_id=http%3A%2F%2Fwww.calconnect.org%2Fresources%2Fintroduction-internet-calendaring&rfr_id=info%3Asid%2Fen.wikipedia.org%3AICalendar" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://icalendar.org/resources.html">"iCalendar Resources"</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=iCalendar+Resources&rft_id=https%3A%2F%2Ficalendar.org%2Fresources.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AICalendar" class="Z3988"></span>: A list of resources for iCalendar and related standards.</li></ul>    </div><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?useformat=desktop&type=1x1&usesul3=0" alt="" width="1" height="1" style="border: none; position: absolute;"></noscript> <div class="printfooter" data-nosnippet="">Retrieved from "<a dir="ltr" href="https://en.wikipedia.org/w/index.php?title=ICalendar&oldid=1261197471">https://en.wikipedia.org/w/index.php?title=ICalendar&oldid=1261197471</a>"</div></div> <div id="catlinks" class="catlinks" data-mw="interface"><div id="mw-normal-catlinks" class="mw-normal-catlinks"><a href="/wiki/Help:Category" title="Help:Category">Categories</a>: <ul><li><a href="/wiki/Category:Computer_file_formats" title="Category:Computer file formats">Computer file formats</a></li><li><a href="/wiki/Category:Calendaring_standards" title="Category:Calendaring standards">Calendaring standards</a></li><li><a href="/wiki/Category:Internet_Standards" title="Category:Internet Standards">Internet Standards</a></li></ul></div><div id="mw-hidden-catlinks" class="mw-hidden-catlinks mw-hidden-cats-hidden">Hidden categories: <ul><li><a href="/wiki/Category:CS1_maint:_others" title="Category:CS1 maint: others">CS1 maint: others</a></li><li><a href="/wiki/Category:Articles_with_short_description" title="Category:Articles with short description">Articles with short description</a></li><li><a href="/wiki/Category:Short_description_is_different_from_Wikidata" title="Category:Short description is different from Wikidata">Short description is different from Wikidata</a></li><li><a href="/wiki/Category:Wikipedia_articles_needing_clarification_from_December_2008" title="Category:Wikipedia articles needing clarification from December 2008">Wikipedia articles needing clarification from December 2008</a></li></ul></div></div> </div> </main> </div> <div class="mw-footer-container"> <footer id="footer" class="mw-footer" > <ul id="footer-info"> <li id="footer-info-lastmod"> This page was last edited on 4 December 2024, at 20:17<span class="anonymous-show"> (UTC)</span>.</li> <li id="footer-info-copyright">Text is available under the <a href="/wiki/Wikipedia:Text_of_the_Creative_Commons_Attribution-ShareAlike_4.0_International_License" title="Wikipedia:Text of the Creative Commons Attribution-ShareAlike 4.0 International License">Creative Commons Attribution-ShareAlike 4.0 License</a>; additional terms may apply. By using this site, you agree to the <a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Terms_of_Use" class="extiw" title="foundation:Special:MyLanguage/Policy:Terms of Use">Terms of Use</a> and <a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy" class="extiw" title="foundation:Special:MyLanguage/Policy:Privacy policy">Privacy Policy</a>. Wikipedia® is a registered trademark of the <a rel="nofollow" class="external text" href="https://wikimediafoundation.org/">Wikimedia Foundation, Inc.</a>, a non-profit organization.</li> </ul> <ul id="footer-places"> <li id="footer-places-privacy"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy">Privacy policy</a></li> <li id="footer-places-about"><a href="/wiki/Wikipedia:About">About Wikipedia</a></li> <li id="footer-places-disclaimers"><a href="/wiki/Wikipedia:General_disclaimer">Disclaimers</a></li> <li id="footer-places-contact"><a href="//en.wikipedia.org/wiki/Wikipedia:Contact_us">Contact Wikipedia</a></li> <li id="footer-places-wm-codeofconduct"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Universal_Code_of_Conduct">Code of Conduct</a></li> <li id="footer-places-developers"><a href="https://developer.wikimedia.org">Developers</a></li> <li id="footer-places-statslink"><a href="https://stats.wikimedia.org/#/en.wikipedia.org">Statistics</a></li> <li id="footer-places-cookiestatement"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Cookie_statement">Cookie statement</a></li> <li id="footer-places-mobileview"><a href="//en.m.wikipedia.org/w/index.php?title=ICalendar&mobileaction=toggle_view_mobile" class="noprint stopMobileRedirectToggle">Mobile view</a></li> </ul> <ul id="footer-icons" class="noprint"> <li id="footer-copyrightico"><a href="https://wikimediafoundation.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><img src="/static/images/footer/wikimedia-button.svg" width="84" height="29" alt="Wikimedia Foundation" loading="lazy"></a></li> <li id="footer-poweredbyico"><a href="https://www.mediawiki.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><img src="/w/resources/assets/poweredby_mediawiki.svg" alt="Powered by MediaWiki" width="88" height="31" loading="lazy"></a></li> </ul> </footer> </div> </div> </div> <div class="vector-settings" id="p-dock-bottom"> <ul></ul> </div><script>(RLQ=window.RLQ||[]).push(function(){mw.config.set({"wgHostname":"mw-web.codfw.main-7fd659d96c-xwhw2","wgBackendResponseTime":159,"wgPageParseReport":{"limitreport":{"cputime":"0.628","walltime":"0.962","ppvisitednodes":{"value":7653,"limit":1000000},"postexpandincludesize":{"value":74490,"limit":2097152},"templateargumentsize":{"value":7562,"limit":2097152},"expansiondepth":{"value":18,"limit":100},"expensivefunctioncount":{"value":16,"limit":500},"unstrip-depth":{"value":1,"limit":20},"unstrip-size":{"value":118655,"limit":5000000},"entityaccesscount":{"value":0,"limit":400},"timingprofile":["100.00% 888.823 1 -total"," 23.75% 211.084 1 Template:Reflist"," 16.86% 149.899 2 Template:Annotated_link"," 15.62% 138.860 1 Template:Infobox_file_format"," 15.54% 138.094 5 Template:Cite_IETF"," 14.98% 133.157 1 Template:Infobox"," 14.09% 125.241 21 Template:IETF_RFC"," 11.37% 101.058 1 Template:Short_description"," 8.72% 77.531 21 Template:Catalog_lookup_link"," 8.30% 73.779 2 Template:Pagetype"]},"scribunto":{"limitreport-timeusage":{"value":"0.351","limit":"10.000"},"limitreport-memusage":{"value":18188008,"limit":52428800}},"cachereport":{"origin":"mw-web.codfw.main-59b954b7fb-7f5nh","timestamp":"20241207162026","ttl":2592000,"transientcontent":false}}});});</script> <script type="application/ld+json">{"@context":"https:\/\/schema.org","@type":"Article","name":"ICalendar","url":"https:\/\/en.wikipedia.org\/wiki\/ICalendar","sameAs":"http:\/\/www.wikidata.org\/entity\/Q284651","mainEntity":"http:\/\/www.wikidata.org\/entity\/Q284651","author":{"@type":"Organization","name":"Contributors to Wikimedia projects"},"publisher":{"@type":"Organization","name":"Wikimedia Foundation, Inc.","logo":{"@type":"ImageObject","url":"https:\/\/www.wikimedia.org\/static\/images\/wmf-hor-googpub.png"}},"datePublished":"2003-08-21T21:30:47Z","dateModified":"2024-12-04T20:17:53Z","headline":"computer file format"}</script> </body> </html>