The Longitude
The longitude against which Indian Standard time is set passes through Allahabad, India.
British India did not adopt the international standard time zones until 1905 when the meridian passing through Allahabad at 82.5º east (of Greenwich Meridian) longitude was picked as the central meridian for India, corresponding to a single time zone for the country at 5 hours and 30 minutes in advance of GMT.
This went into force on January 1, 1906. However, Calcutta time was officially maintained as a separate time zone until 1948. Bombay time was maintained but only informally until about 1955.
After independence and the partition of British India, Pakistan stayed on Indian Standard Time for three years and adopted Pakistan Standard Time at 5 hours in advance of GMT in 1951
Indian Standard Time (IST) is the time observed throughout India and Sri Lanka, with a time offset of UTC+05:30. India does not observe Daylight Saving Time(DST) or other seasonal adjustments. In military and aviation time IST is designated E* ("Echo-Star").[1]
Indian Standard Time is calculated on the basis of 82.5° E longitude, from a clock tower in Mirzapur (25.15°N 82.58°E) (near Allahabad in the state of Uttar Pradesh) which is nearly on the corresponding longitude reference line.[2]
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History [edit]
Main article: Time in India
After independence in 1947, the Indian government established IST as the official time for the whole country, although Kolkata and Mumbai retained their own local time (known as Calcutta time and Bombay Time) until 1955.[3] The Central observatory was moved from Chennai to a location near Mirzapur, so that it would be as close to UTC +5:30 as possible.
Daylight Saving Time (DST) was used briefly during the Sino–Indian War of 1962 and the Indo–Pakistani Wars of 1965 and 1971.[4]
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Criticism and proposals [edit]
The country's east–west distance of more than 2,933 km
British India did not adopt the international standard time zones until 1905 when the meridian passing through Allahabad at 82.5º east (of Greenwich Meridian) longitude was picked as the central meridian for India, corresponding to a single time zone for the country at 5 hours and 30 minutes in advance of GMT.
This went into force on January 1, 1906. However, Calcutta time was officially maintained as a separate time zone until 1948. Bombay time was maintained but only informally until about 1955.
After independence and the partition of British India, Pakistan stayed on Indian Standard Time for three years and adopted Pakistan Standard Time at 5 hours in advance of GMT in 1951
Indian Standard Time (IST) is the time observed throughout India and Sri Lanka, with a time offset of UTC+05:30. India does not observe Daylight Saving Time(DST) or other seasonal adjustments. In military and aviation time IST is designated E* ("Echo-Star").[1]
Indian Standard Time is calculated on the basis of 82.5° E longitude, from a clock tower in Mirzapur (25.15°N 82.58°E) (near Allahabad in the state of Uttar Pradesh) which is nearly on the corresponding longitude reference line.[2]
-------------------------------------------------
History [edit]
Main article: Time in India
After independence in 1947, the Indian government established IST as the official time for the whole country, although Kolkata and Mumbai retained their own local time (known as Calcutta time and Bombay Time) until 1955.[3] The Central observatory was moved from Chennai to a location near Mirzapur, so that it would be as close to UTC +5:30 as possible.
Daylight Saving Time (DST) was used briefly during the Sino–Indian War of 1962 and the Indo–Pakistani Wars of 1965 and 1971.[4]
-------------------------------------------------
Criticism and proposals [edit]
The country's east–west distance of more than 2,933 km