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">Popular standards</a></div> <h1>ISO 8601</h1> <h2 class="mt-0 ">Date and time format</h2></nav></div></div> </div> </section><section id="section-highlight" class="section-highlight mt-0 bg-lightgray"> <div class="container"> <div class="row row-title " > <div class="col-md-12"></div></div><div class="row " > <div class="col-md-7"><p class="lead">Looking for an unambiguous calendar-and-clock format that is internationally understood? It’s time for ISO 8601.</p> <p>This ISO standard helps remove doubts that can result from the various day–date conventions, cultures and time zones that impact a global operation. It gives a way of presenting dates and times that is clearly defined and understandable to both people and machines.</p></div> <div class="col-md-4 col-md-offset-1"></div></div></div> </section> <svg class="wave" preserveAspectRatio="none" aria-hidden="true" focusable="false" viewBox="0 0 1440 96" fill="none" xmlns="http://www.w3.org/2000/svg"><path d="m0 96 80-5C160 85 320 75 480 64s320-21 480-21c160 0 320 10 400 16l80 5V0H0v96Z"></path></svg><section id="section-main" class=" "> <div class="container"> <div class="row row-title " > <div class="col-md-12"></div></div><div class="row " > <div class="col-md-7"><h3>What can ISO 8601 do for me?</h3> <p>When dates are represented with numbers they can be interpreted in different ways. For example, 01/05/22 could mean January 5, 2022, or May 1, 2022. On an individual level this uncertainty can be very frustrating, in a business context it can be very expensive. Organizing meetings and deliveries, writing contracts and buying airplane tickets can be very difficult when the date is unclear.</p> <p>ISO 8601 tackles this uncertainty by setting out an internationally agreed way to represent dates:</p> <p>YYYY-MM-DD</p> <p>Therefore, the order of the elements used to express date and time in ISO 8601 is as follows: year, month, day, hour, minutes, seconds, and milliseconds.</p> <p>For example, September 27, 2022 at 6 p.m. is represented as 2022-09-27 18:00:00.000.</p><p>ISO 8601 can be used by anyone who wants to use a standardized way of presenting:</p> <ul> <li>Date</li> <li>Time of day</li> <li>Coordinated Universal Time (UTC)</li> <li>Local time with offset to UTC</li> <li>Date and time</li> <li>Time intervals</li> <li>Recurring time intervals</li> </ul></div> <div class="col-md-4 col-md-offset-1"><div class="media clearfix square media-news" id="media-news_Ref2164"> <div class="media-left"> <figure class=""> <a href="/news/2017/02/Ref2164.html" title="Date and time: the new draft of ISO 8601 explained by Klaus-Dieter Naujok" aria-label="Date and time: the new draft of ISO 8601 explained by Klaus-Dieter Naujok"><img loading="lazy" src="/files/live/sites/isoorg/files/archive/Ref2164/img_ref2164_01.jpg/thumbnails/150x150" srcset="/files/live/sites/isoorg/files/archive/Ref2164/img_ref2164_01.jpg/thumbnails/150x150 150w, /files/live/sites/isoorg/files/archive/Ref2164/img_ref2164_01.jpg/thumbnails/300x300 300w" sizes="100px" class="img-fluid hover-zoom" alt="" /> </a></figure> </div> <div class="media-body"> <div class="entry-description small text-muted"> <span class="time text-muted"> <time class='updated' datetime='2017-02-21'>21 February 2017</time> </span> </div> <div class="entry-header"> <div class="h5"> <a href="/news/2017/02/Ref2164.html" title="" ><span class="entry-name">Date and time: the new draft of ISO 8601 explained by Klaus-Dieter Naujok</span></a></div> <div class="entry-summary"> Standardization is a truly international activity, and I’ve been lucky to have worked with more nationalities than I can remember. But, that said, my first business meeting with a German remains etched …</div> </div> </div> </div></div></div></div> </section><section class=" bg-danger"> <div class="container"> <div class="row " > <div class="col-md-4"><h2>Highlights from our store</h2></div> <div class="col-md-7 col-md-offset-1"><ul class="refine"><li><div class="clearfix hero-standard" id="hero-standard_70907"> <div class="h4"> <a href="/standard/70907.html"><span class="entry-name">ISO 8601-1:2019</span></a><div class="entry-title">Date and time</div></div> <div class="entry-description">Representations for information interchange – Part 1: Basic rules</div> </div></li><li><div class="clearfix hero-standard" id="hero-standard_70908"> <div class="h4"> <a href="/standard/70908.html"><span class="entry-name">ISO 8601-2:2019</span></a><div class="entry-title">Date and time</div></div> <div class="entry-description">Representations for information interchange – Part 2: Extensions</div> </div></li></ul></div></div> </div> </section><div class="nav-breadcrumb print-footer bg-black"> <div class="container"> <div class="row"> <div class="col-sm-10 small">  <ol class="breadcrumb"> <li class="breadcrumb-item"><a href="/home.html" title="Home page"><i class="bi-house" aria-hidden="true"></i></a></li> <li class="breadcrumb-item"> <a href="/standards.html">Standards</a> </li> <li class="breadcrumb-item"> <a href="/popular-standards.html">Popular standards</a> </li> <li class="breadcrumb-item"> ISO 8601 — Date and time format</li> </ol></div> <div class="col-sm-2 hidden-print text-end small mt-3 mt-sm-0"> <a role="button" class="dropdown-toggle text-white collapsed" data-bs-toggle="collapse" href="#collapseSitemap" target="_self" aria-expanded="false" aria-controls="collapseSitemap">Sitemap</a> </div> </div> <div class="collapse border-top" id="collapseSitemap"> <div class="row">  <nav role="navigation" aria-label="Sitemap" class="sitemap-footer clearfix text-xs" id="nav-sitemap"><ul role='menubar' class='list-inline-6 clearfix nav-level1' ><li role='menuitem' class=' hasChildren inPath firstInLevel' ><a class='nav-link ' title="Covering almost every product, process or service imaginable, ISO makes standards used everywhere." href='/standards.html'>Standards</a><ul role='menubar' class='list-unstyled nav-level2' ><li role='menuitem' class=' noChildren firstInLevel' ><a class='nav-link ' title="Whether you run a business, work for a company or government, or you are a consumer looking for goods and services that meet customer expectations: Find out what standards can do for you." href='/benefits-of-standards.html'>Benefits</a></li><li role='menuitem' class=' noChildren inPath ' ><a class='nav-link ' title="Here you can discover some of the best-known and most widely-used standards, as well as those that address recently emerged challenges affecting us all. 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