Two Time Zones: India's Time Zones were first established in 1884. Originally there were two time zones, Bombay Time and Calcutta Time. In the very early days of railways in India, local time was observed at each large city, in common with practice in most other countries at the time.
Presently, only one time zone known as IST(Indian Standard Time).
Its GMT +5:30Hrs i.e., 5:30 hrs ahead of GMT (Greenwich Mean Time).
India does not have any Daylight Saving Time & Seasonal adjustments.