Indian
Time Meridian (IST) - Allahabad, India
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.
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.
Map of Allahabad, India