{"id":83,"date":"2013-09-01T19:48:00","date_gmt":"2013-09-01T19:48:00","guid":{"rendered":"https:\/\/www.mapsofindia.com\/on-this-day\/1st-september-1947-indian-standard-time-is-introduced\/"},"modified":"2013-09-01T19:48:00","modified_gmt":"2013-09-01T19:48:00","slug":"1st-september-1947-indian-standard-time-is-introduced","status":"publish","type":"post","link":"https:\/\/www.mapsofindia.com\/on-this-day\/1st-september-1947-indian-standard-time-is-introduced","title":{"rendered":"1st September 1947: Indian Standard Time is introduced"},"content":{"rendered":"<p><span style=\"font-size: small;\"><strong>\u00a0<\/strong><\/span>\ufeff<\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">On 1<sup>st<\/sup> September 1947 the Indian Standard Time (IST) was introduced as the official time for the whole country. <\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">\u00a0<\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">The Indian Standard Time is observed throughout India, with a time offset of UTC+5:30. This means that India is five and a half hours ahead of Greenwich Mean Time. Unlike other countries, India does not observe Daylight Saving Time. Indian Standard Time is computed on the basis of 82.5 degrees East longitude from a clock tower in Mirzapur near Allahabad, as it near the corresponding longitude reference line. <\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">\u00a0<\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">Earlier in the 4<sup>th<\/sup>\u00a0century CE\ufeff, an astronomical treatise \u201cSurya Siddhanta\u201d\ufeff\u00a0had mentioned about Standard Time in India. Assuming to which, the earth is spherical. The book outlined that the Prime Meridian passed through Avanti (ancient name for the city of Ujjain) at <span style=\"background-position: initial initial; background-repeat: initial initial;\">23\u00b011\u2032N 75\u00b045\u2032E and Rohitaka (ancient name for Rohtak) at 28\u00b054\u2032N 76\u00b038\u2032E. The book also elaborates that Rohatika and Avanti are situated on a line which passes through the Equator (76\u00b0 E) and the North Pole. <\/span><\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">\u00a0<\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">A sidereal day in ancient India began with sunrise at the Prime Meridian in Ujjain and then was divided into smaller time units. Despite these early advancements standard time was not used other than in astrology. In ancient India, kingdoms used Hindu calenders to keep their own local time. An early example of this is the Jantar Mantar constructed by Maharaja Sawai Jai Singh in 1733 in Jaipur which has large sundials (up to 90 feet high) which were used to accurately\u00a0\ufeffcalculate local time. <\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">\u00a0<\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">The Madras Observatory was established by\u00a0the British East India Company in 1792 primarily because of the efforts of Michael Topping, a sailor and astronomer. In 1802, the first official astronomer of the British East India Company, John Goldingham established the longitude of Chennai as 13\u00b05\u203224\u2033N,<span class=\"apple-converted-space\">\u00a0<\/span>80\u00b018\u203230\u2033E, which was five hours and thirty minutes ahead of Greenwich Mean Time. This was the first time that a current time zone had been used. Following this, as opposed to earlier when a day would begin at sunrise, a day now began at midnight. <\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">\u00a0<\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">Despite this, most towns and cities continued using their own local times until the introduction of the railways in the 1850\u2019s. This was when it became crucial to have a unified time zone. Being the headquarters of the most important presidencies of British India, Mumbai and Kolkata time assumed importance and began to be adopted by nearby provinces and princely states. <\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">\u00a0<\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">In the 19<sup>th<\/sup> century, the railways began to synchronize their clocks through a time signal which would be sent by the head office at a specific time every day. The International Meridian Conference in Washington DC in 1884 established uniform time zones for across the world. Accordingly, India would have two time zones; Kolkata using the 90<sup>th<\/sup> East Meridian and Mumbai the 75<sup>th<\/sup> East Meridian. Kolkata time was set 5 hours, 30 minutes and 21 seconds in advance of the Greenwich Mean Time and Mumbai time was 4 hours, 51 minutes ahead of Greenwich Mean Time. <\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">\u00a0<\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">By the late 1880\u2019s the railways had begun to use the Madras Time (which had come to be known as Railway Time) as an intermediate between the two time zones. Another time zone, the Port Blair Time Zone was established, which was 49 minutes and 51 seconds ahead to the Madras Time. <\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">\u00a0<\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">It was not until 1905 that British India adopted standardized time zones. The meridian passing east of Allahabad was picked as the central meridian for India. This came into force on 1<sup>st<\/sup> January 1906, though Kolkata and Mumbai maintained their own time zone until 1948 and 1955, respectively. <\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">\u00a0<\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">After Independence, on 1<sup>st<\/sup> September 1947, the Indian Government declared the Indian Standard Time as the official time for the entire country (except Kolkata and Mumbai which were to maintain their own time zones for some time to come). The Central Observatory was moved from Chennai to Mirzapur so that it would be closer to the UTC+5:30. Though India does not observe Daylight Saving Time, it was observed briefly during the Sino-Indian war in 1962 and the Indo-Pakistani wars in 1965 and 1971 respectively, so that energy consumption by civilians would be reduced. <\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">\u00a0<\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\"><em>Also on This Day<\/em>:<\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">\u00a0<\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">1858: Court of Directors of the East India Company held its last meeting in the East India House in London.<\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">\u00a0<\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">1942: Indian National Army was founded by Rash Behari Bose.<\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">\u00a0<\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: small;\">1956: Pakistani forces crossed the ceasefire line in Kashmir.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u00a0\ufeff On 1st September 1947 the Indian Standard Time (IST) was introduced as the official time for the whole country. \u00a0 The Indian Standard Time is observed throughout India, with a time offset of UTC+5:30. This means that India is five and a half hours ahead of Greenwich Mean Time. Unlike other countries, India does not observe Daylight Saving Time&#8230;. <\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-83","post","type-post","status-publish","format-standard","hentry","category-history"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v23.2 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>1st September 1947: Indian Standard Time is introduced -<\/title>\n<meta name=\"description\" content=\"- 1st September 1947: Indian Standard Time is introduced\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.mapsofindia.com\/on-this-day\/1st-september-1947-indian-standard-time-is-introduced\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"1st September 1947: Indian Standard Time is introduced -\" \/>\n<meta property=\"og:description\" content=\"- 1st September 1947: Indian Standard Time is introduced\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.mapsofindia.com\/on-this-day\/1st-september-1947-indian-standard-time-is-introduced\" \/>\n<meta property=\"og:site_name\" content=\"What Happened on This Day in History - Maps of India\" \/>\n<meta property=\"article:published_time\" content=\"2013-09-01T19:48:00+00:00\" \/>\n<meta name=\"author\" content=\"admin\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"admin\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"4 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.mapsofindia.com\/on-this-day\/1st-september-1947-indian-standard-time-is-introduced\",\"url\":\"https:\/\/www.mapsofindia.com\/on-this-day\/1st-september-1947-indian-standard-time-is-introduced\",\"name\":\"1st September 1947: Indian Standard Time is introduced -\",\"isPartOf\":{\"@id\":\"https:\/\/www.mapsofindia.com\/on-this-day\/#website\"},\"datePublished\":\"2013-09-01T19:48:00+00:00\",\"dateModified\":\"2013-09-01T19:48:00+00:00\",\"author\":{\"@id\":\"https:\/\/www.mapsofindia.com\/on-this-day\/#\/schema\/person\/ba1af40a376d3aa913150351dd75ec6d\"},\"description\":\"- 1st September 1947: Indian Standard Time is introduced\",\"breadcrumb\":{\"@id\":\"https:\/\/www.mapsofindia.com\/on-this-day\/1st-september-1947-indian-standard-time-is-introduced#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.mapsofindia.com\/on-this-day\/1st-september-1947-indian-standard-time-is-introduced\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.mapsofindia.com\/on-this-day\/1st-september-1947-indian-standard-time-is-introduced#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/www.mapsofindia.com\/on-this-day\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"1st September 1947: Indian Standard Time is introduced\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.mapsofindia.com\/on-this-day\/#website\",\"url\":\"https:\/\/www.mapsofindia.com\/on-this-day\/\",\"name\":\"What Happened on This Day in History - Maps of India\",\"description\":\"Know what happened today in the history of India - Find which important historical event took place on this day in the Indian history.\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/www.mapsofindia.com\/on-this-day\/?s={search_term_string}\"},\"query-input\":\"required name=search_term_string\"}],\"inLanguage\":\"en-US\"},{\"@type\":\"Person\",\"@id\":\"https:\/\/www.mapsofindia.com\/on-this-day\/#\/schema\/person\/ba1af40a376d3aa913150351dd75ec6d\",\"name\":\"admin\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.mapsofindia.com\/on-this-day\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/1a914a0c6c577662f19ad97f13763d2c?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/1a914a0c6c577662f19ad97f13763d2c?s=96&d=mm&r=g\",\"caption\":\"admin\"},\"url\":\"https:\/\/www.mapsofindia.com\/on-this-day\/author\/admin\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"1st September 1947: Indian Standard Time is introduced -","description":"- 1st September 1947: Indian Standard Time is introduced","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.mapsofindia.com\/on-this-day\/1st-september-1947-indian-standard-time-is-introduced","og_locale":"en_US","og_type":"article","og_title":"1st September 1947: Indian Standard Time is introduced -","og_description":"- 1st September 1947: Indian Standard Time is introduced","og_url":"https:\/\/www.mapsofindia.com\/on-this-day\/1st-september-1947-indian-standard-time-is-introduced","og_site_name":"What Happened on This Day in History - Maps of India","article_published_time":"2013-09-01T19:48:00+00:00","author":"admin","twitter_card":"summary_large_image","twitter_misc":{"Written by":"admin","Est. reading time":"4 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/www.mapsofindia.com\/on-this-day\/1st-september-1947-indian-standard-time-is-introduced","url":"https:\/\/www.mapsofindia.com\/on-this-day\/1st-september-1947-indian-standard-time-is-introduced","name":"1st September 1947: Indian Standard Time is introduced -","isPartOf":{"@id":"https:\/\/www.mapsofindia.com\/on-this-day\/#website"},"datePublished":"2013-09-01T19:48:00+00:00","dateModified":"2013-09-01T19:48:00+00:00","author":{"@id":"https:\/\/www.mapsofindia.com\/on-this-day\/#\/schema\/person\/ba1af40a376d3aa913150351dd75ec6d"},"description":"- 1st September 1947: Indian Standard Time is introduced","breadcrumb":{"@id":"https:\/\/www.mapsofindia.com\/on-this-day\/1st-september-1947-indian-standard-time-is-introduced#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.mapsofindia.com\/on-this-day\/1st-september-1947-indian-standard-time-is-introduced"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/www.mapsofindia.com\/on-this-day\/1st-september-1947-indian-standard-time-is-introduced#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.mapsofindia.com\/on-this-day"},{"@type":"ListItem","position":2,"name":"1st September 1947: Indian Standard Time is introduced"}]},{"@type":"WebSite","@id":"https:\/\/www.mapsofindia.com\/on-this-day\/#website","url":"https:\/\/www.mapsofindia.com\/on-this-day\/","name":"What Happened on This Day in History - Maps of India","description":"Know what happened today in the history of India - Find which important historical event took place on this day in the Indian history.","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.mapsofindia.com\/on-this-day\/?s={search_term_string}"},"query-input":"required name=search_term_string"}],"inLanguage":"en-US"},{"@type":"Person","@id":"https:\/\/www.mapsofindia.com\/on-this-day\/#\/schema\/person\/ba1af40a376d3aa913150351dd75ec6d","name":"admin","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.mapsofindia.com\/on-this-day\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/1a914a0c6c577662f19ad97f13763d2c?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/1a914a0c6c577662f19ad97f13763d2c?s=96&d=mm&r=g","caption":"admin"},"url":"https:\/\/www.mapsofindia.com\/on-this-day\/author\/admin"}]}},"_links":{"self":[{"href":"https:\/\/www.mapsofindia.com\/on-this-day\/wp-json\/wp\/v2\/posts\/83"}],"collection":[{"href":"https:\/\/www.mapsofindia.com\/on-this-day\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.mapsofindia.com\/on-this-day\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.mapsofindia.com\/on-this-day\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.mapsofindia.com\/on-this-day\/wp-json\/wp\/v2\/comments?post=83"}],"version-history":[{"count":0,"href":"https:\/\/www.mapsofindia.com\/on-this-day\/wp-json\/wp\/v2\/posts\/83\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.mapsofindia.com\/on-this-day\/wp-json\/wp\/v2\/media?parent=83"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.mapsofindia.com\/on-this-day\/wp-json\/wp\/v2\/categories?post=83"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.mapsofindia.com\/on-this-day\/wp-json\/wp\/v2\/tags?post=83"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}