USA, Canada clocks on Daylight Saving Time until 4 November 2012 at 2am local time
UK / Europe: Clocks on Summer Time until: Sunday 28 October 2012 01:00 (1am) GMT
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.
