Indian time zone | Indian Standard Time, India, Degree, GMT, & UTC

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class="left-rail-section-content"> <div class="topic-left-rail-header text-truncate bg-gray-50 position-relative text-right d-flex align-items-center"> <div class="tlr-title px-20 py-15 text-left"> <em class="material-icons text-gray-400 d-lg-none" data-icon="toc"></em> <a class="font-serif font-weight-bold text-black link-blue" href="https://www.britannica.com/science/Indian-time-zone">Indian time zone</a> </div> <button aria-label="Close" class="js-sections-close-button btn-link btn-sm btn d-lg-none position-absolute top-0 p-10 right-0" > <em class="material-icons font-26" data-icon="close"></em> </button> </div> <div class="section-content pl-10 pr-20 pl-sm-50 pr-sm-60 pl-lg-5 pr-lg-10 pt-10 pt-lg-0 bg-gray-50 clear-catfish-ad"> <div class="toc mb-20"> <div class="font-serif font-14 font-weight-bold mx-15 mb-15 mt-20"> Table of Contents </div> <ul class="list-unstyled my-0" data-level="h1"><li data-target="#ref1"><div class="pl-25"><a class="link-gray-900 w-100" href="/science/Indian-time-zone">Introduction</a></div><div class="ml-40 toc-drawer sub-toc-drawer"></div></li><li data-target="#ref407749"><div class="d-flex align-items-center"><div class="ml-25"></div><a class="w-100 link-gray-900" href="/science/Indian-time-zone#ref407749">Indian Standard Time</a></div><div class="ml-40 toc-drawer sub-toc-drawer"></div></li><li data-target="#ref407750"><div class="d-flex align-items-center"><button class="h1-link-drawer-button btn btn-xs btn-circle d-flex rounded" type="button" aria-label="Toggle Heading"><em class="material-icons font-18" data-icon="keyboard_arrow_right"></em></button><a class="w-100 link-gray-900" href="/science/Indian-time-zone#ref407750">History</a></div><div class="ml-40 toc-drawer sub-toc-drawer"><ul class="list-unstyled" data-level="h2"><li data-target="#ref407751"><a class="w-100 link-gray-900" href="/science/Indian-time-zone#ref407751">Precolonial timekeeping</a></li></ul><ul class="list-unstyled" data-level="h2"><li data-target="#ref407752"><a class="w-100 link-gray-900" href="/science/Indian-time-zone#ref407752">East India Company and railway time</a></li></ul><ul class="list-unstyled" data-level="h2"><li data-target="#ref407753"><a class="w-100 link-gray-900" href="/science/Indian-time-zone#ref407753">International developments</a></li></ul><ul class="list-unstyled" data-level="h2"><li data-target="#ref407754"><a class="w-100 link-gray-900" href="/science/Indian-time-zone#ref407754">Introduction of Indian Standard Time</a></li></ul></div></li><li data-target="#ref407755"><div class="d-flex align-items-center"><div class="ml-25"></div><a class="w-100 link-gray-900" href="/science/Indian-time-zone#ref407755">IST today</a></div><div class="ml-40 toc-drawer sub-toc-drawer"></div></li></ul> <a class="toc-extra-link link-gray-900" href="https://www.britannica.com/science/Indian-time-zone/additional-info">References & Edit History</a> <a class="toc-extra-link link-gray-900" href="/facts/Indian-time-zone">Related Topics</a> </div> <div class="mb-30 tlr-related-questions"> <div class="text-gray-900 p-5 pb-0 font-serif font-14 font-weight-bold mx-10 mb-15"> Related Questions </div> <ul> <li class="link-gray-900 mb-15"><a class="" href="/question/What-does-Earth-look-like">What does Earth look like?</a> </li> <li class="link-gray-900 mb-15"><a class="" href="/question/What-are-the-oldest-known-civilizations-of-India">What are the oldest known civilizations of India?</a> </li> <li class="link-gray-900 mb-15"><a class="" href="/question/What-are-the-major-holidays-and-festivals-of-India">What are the major holidays and festivals of India?</a> </li> </ul> </div> <div class="mb-30 tlr-read-next"> <div class="text-gray-900 p-5 font-serif font-14 font-weight-bold mx-10 mb-10"> Read Next </div> <div class="imagelink-with-image-on-the-side card card-horizontal tlr-img-with-side-link ml-15 link-gray-900 mb-10" > <div class="position-relative card-media" style="flex: 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They write new content and verify and edit content received from contributors.</div> </a> <div data-popper-arrow></div> </div> <span class="btn btn-link editor-link p-0 qa-byline-link font-12 "> The Editors of Encyclopaedia Britannica</span></div> <div class="last-updated font-12 font-serif"> <span class="text-gray-700"> Last Updated: <time datetime="2025-03-12T00:00:00CDT" >Mar 12, 2025</time> •</span> <a class="byline-edit-history" href="https://www.britannica.com/science/Indian-time-zone/additional-info#history" rel="nofollow">Article History</a> </div></div> </div> <button class="d-flex d-lg-none btn btn-outline-blue border rounded-sm shadow-sm mobile-toc-button gtm-mobile-toc-inline-button d-none d-sm-block js-sections-inline-button module-spacing btn d-lg-none"> <em class="material-icons mr-5 ml-n10 my-n5 md-icon" data-icon="toc"></em> Table of Contents </button> <div class="d-flex d-sm-none flex-row"> <button class="d-flex d-lg-none btn btn-outline-blue border rounded-sm shadow-sm mobile-toc-button gtm-mobile-toc-inline-button js-sections-inline-button module-spacing"> <em class="material-icons mr-5 ml-n10 my-n5 md-icon" data-icon="toc"></em> Table of Contents </button> <button class="ai-ask-button btn btn-sm border-2 btn-outline-red-400 border-red-400 module-spacing js-inline-ai-ask-button p-10 ml-5"> Ask the Chatbot </button> </div> <div class="js-qf-module qf-module px-40 px-sm-20 py-15 mx-auto module-spacing font-14 bg-gray-50 rounded"> <div class="facts-list mt-10"> <div class=""> <div class="js-fact mb-10 line-clamp clamp-3"> <dl> <dt>Related Topics: </dt> <dd><a href="/place/India" topicid="285248">India</a></dd> <dd><a href="/science/time-zone" topicid="596215">time zone</a></dd> </dl> <button class="js-more-btn d-none btn btn-unstyled font-12 bg-gray-50" aria-label="Toggle more/less fact data"> <em class="js-content link-blue">(Show more)</em> </button> </div> <div class="text-center"> <a class="btn btn-sm btn-link p-0" href="/facts/Indian-time-zone"> See all related content </a> </div> </div> </div> </div><span class="marker before-article"></span><section data-level="1" id="ref1"><span class="marker PREMOD1 mod-inline"></span><p class="topic-paragraph"><strong><span id="ref1334606"></span>Indian time zone</strong>, <a href="https://www.britannica.com/science/time-zone" class="md-crosslink autoxref " data-show-preview="true">time zone</a> in <a href="https://www.britannica.com/place/India" class="md-crosslink " data-show-preview="true">India</a> observing Indian <a href="https://www.britannica.com/science/Standard-Time" class="md-crosslink autoxref " data-show-preview="true">Standard Time</a> (IST)—five and a half hours ahead of <a href="https://www.britannica.com/science/Coordinated-Universal-Time" class="md-crosslink " data-show-preview="true">Coordinated Universal Time</a> (UTC)—based on the Indian standard <a href="https://www.britannica.com/science/meridian-geography" class="md-crosslink " data-show-preview="true">meridian</a> (82°30′ E), which passes through <a href="https://www.britannica.com/place/Mirzapur-Vindhyachal" class="md-crosslink " data-show-preview="true">Mirzapur</a>, <a href="https://www.britannica.com/place/Uttar-Pradesh" class="md-crosslink " data-show-preview="true">Uttar Pradesh</a>. IST is the sole time zone observed in India across its <a class="md-dictionary-link md-dictionary-tt-off eb" data-term="vast" href="https://www.britannica.com/dictionary/vast" data-type="EB">vast</a> east-west expanse. Using one time zone for the country, which spans more than 1,800 miles (2,900 km) from east to west, ensures standardization between cities that have huge variations in their local solar schedules. This resolves historical timekeeping issues while also creating regional challenges.</p><span class="marker MOD1 mod-inline"></span></section> <span class="marker h2"></span><section data-level="1" id="ref407749"> <h2 class="h1">Indian Standard Time</h2> <span class="marker PREMOD2 mod-inline"></span><p class="topic-paragraph">India spans about 30 degrees of longitude wide. Since <a href="https://www.britannica.com/place/Earth" class="md-crosslink autoxref " data-show-preview="true">Earth</a> rotates 360° in 24 hours, every 15° of longitude corresponds to a one-hour time difference. This means that, without a standard time, India’s westernmost and easternmost regions would have a natural two-hour difference in local time.</p><span class="marker MOD2 mod-inline"></span> <span class="marker PREMOD3 mod-inline"></span><p class="topic-paragraph">Indian Standard Time is observed as UTC+5:30 to <a class="md-dictionary-link md-dictionary-tt-off eb" data-term="synchronize" href="https://www.britannica.com/dictionary/synchronize" data-type="EB">synchronize</a> time in the country by balancing such local offsets in time. This time offset is derived from the country’s standard meridian at 82°30′ E. Since 60′ make up 1° of longitude, 30′ is half a degree, which means the standard meridian can be expressed as 82.5° E. Every 15° of longitude corresponds to a one-hour time difference, so dividing 82.5° by 15 gives a 5.5-hour offset. Since this meridian is east of <a href="https://www.britannica.com/place/Greenwich-meridian" class="md-crosslink " data-show-preview="true">0° longitude</a>, IST is 5.5 hours ahead of UTC.</p><div class="module-spacing"> </div><span class="marker MOD3 mod-inline"></span> </section> <span class="marker h3"></span><section data-level="1" id="ref407750"> <h2 class="h1">History</h2> <span class="marker PREMOD4 mod-inline"></span><p class="topic-paragraph">Timekeeping practices in India have shifted from traditional astronomical methods to calculate local times for regions in the precolonial period to a single national time zone.</p><span class="marker MOD4 mod-inline"></span> <section data-level="2" id="ref407751"> <h2 class="h2">Precolonial timekeeping</h2> <span class="marker PREMOD5 mod-inline"></span><p class="topic-paragraph">Regions in precolonial India kept time through solar and lunar calculations. Indian astronomical traditions codified time calculations, as seen in the 4th-century <span class="text-smallcaps">ce</span> <a class="md-dictionary-link md-dictionary-tt-off mw" data-term="treatise" href="https://www.merriam-webster.com/dictionary/treatise" data-type="MW">treatise</a> <em>Surya Siddhanta</em>, which mentions a “prime meridian” passing through <a href="https://www.britannica.com/place/Avanti-ancient-kingdom-India" class="md-crosslink " data-show-preview="true">Avanti</a> (identified as the region near <a href="https://www.britannica.com/place/Ujjain" class="md-crosslink " data-show-preview="true">Ujjain</a> in present-day <a href="https://www.britannica.com/place/Madhya-Pradesh" class="md-crosslink " data-show-preview="true">Madhya Pradesh</a> state). The text provides detailed units of time and methods to convert daylight times from various other regions to Ujjain time.</p><span class="marker MOD5 mod-inline"></span> </section> <section data-level="2" id="ref407752"> <h2 class="h2">East India Company and railway time</h2> <div class="feature-block callout"><div class="font-weight-bold">Madras Observatory</div><p class="topic-paragraph">In 1786 <a href="https://www.britannica.com/topic/East-India-Company" class="md-crosslink autoxref " data-show-preview="true">British East India Company</a> officer William Petrie created a private observatory in Egmore in present-day Chennai. On his return to England in 1789, Petrie gave the observatory equipment to the Madras government. Michael Topping, the East India Company’s astronomer and surveyor, used Petrie’s equipment and framework to establish the Madras Observatory in Nungambakkam, also now in Chennai, setting up Asia’s first modern observatory. When its equipment and some staff were shifted to an observatory established by the company in <a href="https://www.britannica.com/place/Kodaikanal" class="md-crosslink " data-show-preview="true">Kodaikanal</a> in 1899, the Madras Observatory gradually lost prominence, though it continued to be used for astronomical observation to regulate Indian Standard Time until it was closed in 1931.</p></div> <span class="marker PREMOD6 mod-inline"></span><p class="topic-paragraph">Early in India’s colonial period, the <a href="https://www.britannica.com/topic/presidencies-in-British-India-Bombay-Madras-and-Bengal" class="md-crosslink " data-show-preview="true">Bombay and Bengal presidencies</a> defined time based on local solar conditions. In the Madras Presidency John Goldingham, the first head of Madras Observatory—Asia’s first modern observatory—calculated Madras Time against <a href="https://www.britannica.com/science/Greenwich-Mean-Time" class="md-crosslink autoxref " data-show-preview="true">Greenwich Mean Time</a> (GMT) as GMT+5:21:14 (5 hours 21 minutes 14 seconds ahead of GMT) in 1802. The company used this calculation to record local time in the Madras Presidency.</p><span class="marker MOD6 mod-inline"></span> <span class="marker PREMOD7 mod-inline"></span><p class="topic-paragraph">The growing importance of the railways and the <a href="https://www.britannica.com/technology/telegraph" class="md-crosslink " data-show-preview="true">telegraph</a> prompted British authorities to <a class="md-dictionary-link md-dictionary-tt-off mw" data-term="implement" href="https://www.merriam-webster.com/dictionary/implement" data-type="MW">implement</a> a standard time for railway operations from the 1850s onward, as frequent conversions between local times for departures and arrivals caused scheduling confusion. They chose Madras Time for this, because Madras (now <a href="https://www.britannica.com/place/Chennai" class="md-crosslink " data-show-preview="true">Chennai</a>) was roughly midway between the Bombay and Bengal presidencies, and the Madras Observatory, which ran the telegraph service used to synchronize railway station times, helped regulate this time. Initially the difference between railway time and local time would be noted in railway timetables and travel guides, and two time references would thus coexist at railway stations: Madras Time and local time based on solar patterns. British authorities tried to standardize Madras Time with little success. For instance, in 1881, the governor of Bombay tried <a class="md-dictionary-link md-dictionary-tt-off eb" data-term="imposing" href="https://www.britannica.com/dictionary/imposing" data-type="EB">imposing</a> it on civilians in Bombay. This led to considerable dissent, and local time was restored in 1883. Local times largely continued to coexist with Madras Time wherever the railways had stations.</p><div class="module-spacing"> <DIV class="marketing-INLINE_SUBSCRIPTION marketing-content" data-marketing-id="INLINE_SUBSCRIPTION"><style> .student-promo-banner-wrapper { container-type: inline-size; margin-bottom: 15px; } @container (min-width: 475px) { .student-promo-banner { flex-direction: row; } .student-promo-banner-img-wrapper { margin-bottom: 0; margin-right: 10px; justify-content: flex-start; } .student-promo-banner-text-wrapper { text-align: left; margin-bottom: 0px; margin-left: 10px; } .student-promo-banner-button-wrapper { margin-right: 0; } }</style> <div class="student-promo-banner-wrapper"> <div class="student-promo-banner d-flex flex-column align-items-center bg-blue rounded p-20"> <div class="student-promo-banner-img-wrapper mb-20 mr-0 d-flex justify-content-center"> <img class="rounded" style="max-width: 100px; min-width: 80px" src="https://cdn.britannica.com/marketing/BlueThistle.webp" /> </div> <div class="student-promo-banner-text-wrapper ml-0 mb-10 text-center text-white"> <div class="h2 mb-10">Get Unlimited Access</div> <div class="h4 font-weight-semi-bold">Try Britannica Premium for free and discover more.</div> </div> <div class="student-promo-banner-button-wrapper d-flex justify-content-center align-items-center ml-auto mr-auto"> <a class="btn btn-m btn-orange" href="https://premium.britannica.com/premium-membership/?utm_source=premium&utm_medium=inline-cta&utm_campaign=august-2024">Subscribe</a> </div> </div> </div> </DIV></div><span class="marker MOD7 mod-inline"></span> </section> <section data-level="2" id="ref407753"> <h2 class="h2">International developments</h2> <span class="marker PREMOD8 mod-inline"></span><p class="topic-paragraph">In 1884 the International Meridian Conference was held in <a href="https://www.britannica.com/place/Washington-DC" class="md-crosslink " data-show-preview="true">Washington, D.C.</a>, to attempt to standardize time globally. It proposed to set the <a href="https://www.britannica.com/place/Greenwich-meridian" class="md-crosslink " data-show-preview="true">Greenwich meridian</a> as the prime meridian and calculate times in zones of one-hour increments based on distance from the prime meridian. It posited the use of the 75th meridian for Bombay (now <a href="https://www.britannica.com/place/Mumbai" class="md-crosslink " data-show-preview="true">Mumbai</a>) and the 90th for Calcutta (now <a href="https://www.britannica.com/place/Kolkata" class="md-crosslink " data-show-preview="true">Kolkata</a>), which would have set the standard times in these zones to GMT+5 and GMT+6, respectively. But the conference failed to vote on the use of zones with one-hour increments because of practical difficulties based on political borders, among other reasons. It did succeed in establishing the Greenwich meridian at 0° longitude. This meant that the local times that were observed in Calcutta and Bombay prior to the conference gained global validity as British India’s two official time zones. Defined in terms of offsets to GMT, Bombay’s local time was GMT+4:51:00, whereas that at Calcutta in the Bengal Presidency was GMT+5:53:20. But the use of Madras Time continued, as the new time zones did not offer a single <a class="md-dictionary-link md-dictionary-tt-off mw" data-term="alternative" href="https://www.merriam-webster.com/dictionary/alternative" data-type="MW">alternative</a> standard for the railways to use.</p><span class="marker MOD8 mod-inline"></span> </section> <section data-level="2" id="ref407754"> <h2 class="h2">Introduction of Indian Standard Time</h2> <span class="marker PREMOD9 mod-inline"></span><p class="topic-paragraph">In 1905 Viceroy of India Lord <a href="https://www.britannica.com/biography/Lord-Curzon" class="md-crosslink " data-show-preview="true">Curzon</a> announced that the 82°30′ E longitude passing through <a href="https://www.britannica.com/place/Mirzapur-Vindhyachal" class="md-crosslink " data-show-preview="true">Mirzapur</a>, east of Allahabad (now <a href="https://www.britannica.com/place/Prayagraj" class="md-crosslink " data-show-preview="true">Prayagraj</a>), would be the basis for the new Indian Standard Time (IST). Shortly after this, he also announced the <a href="https://www.britannica.com/event/Partition-of-Bengal" class="md-crosslink " data-show-preview="true">partition of Bengal</a>. These decisions intensified regional dissent against Britain’s imposition of a standard time on civilian schedules. The opposition to nonlocal time in Bombay developed overtones of colonial resistance. Class-based resistance also added to the opposition to the new standard as the already overworked and underpaid Bombay textile mill workers would now have to start their work before dawn. This long-running debate over time came to be called the Battle of the Clocks in local news, and it would be resolved only after independence.</p><span class="marker MOD9 mod-inline"></span> <div class="feature-block callout"><div class="font-weight-bold">The Rejected Royal Society Proposal</div><p class="topic-paragraph">The <a href="https://www.britannica.com/topic/Royal-Society" class="md-crosslink autoxref " data-show-preview="true">Royal Society</a> in London proposed two time zones for India in 1904–05 at one-hour offsets from GMT: GMT+5 and GMT+6. But the colonial government rejected the proposal for two time zones in favor of one falling in the middle of both of the proposed zones, leading to the selection of GMT+5:30 as the offset.</p></div> <span class="marker PREMOD10 mod-inline"></span><p class="topic-paragraph">Meanwhile, British authorities formally adopted the new standard on January 1, 1906, with <a class="md-dictionary-link md-dictionary-tt-off mw" data-term="concessions" href="https://www.merriam-webster.com/dictionary/concessions" data-type="MW">concessions</a> to local times in dissenting regions. Bombay and Calcutta continued to use their own local time until long afterward. Calcutta would adopt IST in 1948, and Bombay would follow suit only in 1955.</p><span class="marker MOD10 mod-inline"></span> </section> </section> <span class="marker h4"></span><section data-level="1" id="ref407755"> <h2 class="h1">IST today</h2> <span class="marker PREMOD11 mod-inline"></span><p class="topic-paragraph">IST was officially adopted by independent India on September 1, 1947, to unify time across the country, simplifying business, government, and transport operations. The <a href="https://www.britannica.com/topic/Council-of-Scientific-and-Industrial-Research" class="md-crosslink " data-show-preview="true">Council of Scientific and Industrial Research</a>’s National Physical Laboratory (CSIR-NPL) at Delhi maintains IST. Though there is no official legislation or <a class="md-dictionary-link md-dictionary-tt-off mw" data-term="constitutional" href="https://www.merriam-webster.com/dictionary/constitutional" data-type="MW">constitutional</a> provision that defines IST, the <a href="https://www.britannica.com/topic/Indian-government" class="md-crosslink autoxref " data-show-preview="true">government of India</a> reinforced the drive to standardize IST implementation with the Draft Legal Metrology (Indian Standard Time) Rules in 2025. These rules make provisions for accurately maintaining IST through dedicated <a href="https://www.britannica.com/science/metrology" class="md-crosslink " data-show-preview="true">metrology</a> centers and <a class="md-dictionary-link md-dictionary-tt-off mw" data-term="mandate" href="https://www.merriam-webster.com/dictionary/mandate" data-type="MW">mandate</a> that government offices and public institutions display IST on all time-keeping devices. They aim to ensure standardization and accuracy in various sectors such as navigation and banking.</p><span class="marker MOD11 mod-inline"></span> <span class="marker PREMOD12 mod-inline"></span><p class="topic-paragraph">Given India’s large east-west extent, a single time zone also presents challenges. In India’s northeastern states—<a href="https://www.britannica.com/place/Arunachal-Pradesh" class="md-crosslink " data-show-preview="true">Arunachal Pradesh</a>, <a href="https://www.britannica.com/place/Assam" class="md-crosslink " data-show-preview="true">Assam</a>, <a href="https://www.britannica.com/place/Manipur" class="md-crosslink " data-show-preview="true">Manipur</a>, <a href="https://www.britannica.com/place/Meghalaya" class="md-crosslink " data-show-preview="true">Meghalaya</a>, <a href="https://www.britannica.com/place/Mizoram" class="md-crosslink " data-show-preview="true">Mizoram</a>, <a href="https://www.britannica.com/place/Nagaland" class="md-crosslink " data-show-preview="true">Nagaland</a>, and <a href="https://www.britannica.com/place/Tripura-state-India" class="md-crosslink " data-show-preview="true">Tripura</a>—the Sun rises almost two hours earlier than in western Indian trade centers such as <a href="https://www.britannica.com/place/Ahmadabad" class="md-crosslink " data-show-preview="true">Ahmedabad</a>. A 2018 study by researchers at the CSIR-NPL and other collaborators posited that starting the day significantly after sunrise in the region leads to lower productivity, as office-goers and students begin their day out of synchronization with <a href="https://www.britannica.com/science/circadian-rhythm" class="md-crosslink " data-show-preview="true">circadian rhythms</a>. It also increases electricity <a class="md-dictionary-link md-dictionary-tt-off mw" data-term="consumption" href="https://www.merriam-webster.com/dictionary/consumption" data-type="MW">consumption</a>, as offices continue to work until after sunset. Conceding the difficulty of <a class="md-dictionary-link md-dictionary-tt-off mw" data-term="implementing" href="https://www.merriam-webster.com/dictionary/implementing" data-type="MW">implementing</a> one time zone over a large east-west expanse, the Plantations Labour Act of 1951 allows state governments to set <a href="https://www.britannica.com/money/hours-of-labour" class="md-crosslink autoxref " data-show-preview="true">working hours</a> for certain industries as per local daylight conditions. For instance, tea plantations in Assam follow an informal time zone one hour ahead of IST called <em>chai bagan</em> (“tea garden”) time.</p><div class="one-good-fact-module"> </div><span class="marker MOD12 mod-inline"></span> <span class="marker PREMOD13 mod-inline"></span><p class="topic-paragraph">The <a href="https://www.britannica.com/topic/Planning-Commission" class="md-crosslink autoxref " data-show-preview="true">Planning Commission</a> proposed using two time zones for the country in 2006, and similar proposals have emerged through public interest litigation and demands from political figures in India over time. The CSIR-NPL proposed a second time zone for states east of <a href="https://www.britannica.com/place/West-Bengal" class="md-crosslink autoxref " data-show-preview="true">West Bengal</a>, IST-II, with the time <a class="md-dictionary-link md-dictionary-tt-off eb" data-term="offset" href="https://www.britannica.com/dictionary/offset" data-type="EB">offset</a> UTC+6:30 based on the longitude 89°52′ E. However, all proposals for a second time zone have been rejected because of logistical challenges.</p><span class="marker MOD13 mod-inline"></span> </section> <span class="md-signature font-12"><a href="/editor/aman-kumar/13094625">Aman Kumar</a></span><span class="marker end-of-content"></span><span class="marker after-article"></span></div> <div id="chatbot-simplify-root"></div> <div id="chatbot-root"></div> </div> </div> </div> <div class="ai-dialog-placeholder"></div> </div> </div> <aside class="col-md-da-320"></aside> </div> </div> </div> </div> </article> </div> </div> </div> </div> </main> <div id="md-footer"></div> <noscript><iframe src="//www.googletagmanager.com/ns.html?id=GTM-5W6NC8" height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript>  <script> window.ap3c = window.ap3c || {}; var ap3c = window.ap3c; ap3c.cmd = ap3c.cmd || []; ap3c.cmd.push(function() { ap3c.init('ZO4siT4cLwnykPnzZWJtd3Byb2Q', 'https://engage.email.britannica.com/'); ap3c.track({v: 0}); }); ap3c.activity = function(act) { ap3c.act = (ap3c.act || []); ap3c.act.push(act); }; var s, t; s = document.createElement('script'); s.type = 'text/javascript'; s.src = "https://engage.email.britannica.com/app.js"; t = document.getElementsByTagName('script')[0]; t.parentNode.insertBefore(s, t); </script> <script class="marketing-page-info" type="application/json"> {"pageType":"Topic","templateName":"DESKTOP","pageNumber":1,"pagesTotal":1,"pageId":2263534,"pageLength":1406,"initialLoad":true,"lastPageOfScroll":false} </script> <script class="marketing-content-info" type="application/json"> [] </script> <script src="https://cdn.britannica.com/mendel-resources/3-134/js/libs/jquery-3.5.0.min.js?v=3.134.9"></script> <script type="text/javascript" data-type="Init Mendel Code Splitting"> (function() { $.ajax({ dataType: 'script', cache: true, url: 'https://cdn.britannica.com/mendel-resources/3-134/dist/topic-page.js?v=3.134.9' }); })(); </script> <script class="analytics-metadata" type="application/json"> {"leg":"C","adLeg":"C","userType":"ANONYMOUS","pageType":"Topic","pageSubtype":null,"articleTemplateType":"LARGE","gisted":false,"pageNumber":1,"hasSummarizeButton":false,"hasAskButton":true,"hasAiTopQuestions":false,"hasSimplifyButton":false} </script> <script type="text/javascript"> EBStat={accountId:-1,hostnameOverride:'webstats.eb.com',domain:'www.britannica.com', json:''}; </script> <script type="text/javascript"> ( function() { $.ajax( { dataType: 'script', cache: true, url: '//www.britannica.com/webstats/mendelstats.js?v=1' } ) .done( function() { try {writeStat(null,EBStat);} catch(err){} } ); })(); </script> <div id="bc-fixed-dialogue"></div> </body> </html>

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Indian time zone | Indian Standard Time, India, Degree, GMT, & UTC | Britannica