What is Indian Standard Time?

Indian Standard Time (IST) is the national time zone for India. It is a UTC+05:30 time zone, which means that it is 5 hours and 30 minutes ahead of Coordinated Universal Time (UTC).

IST is based on the mean solar time at 82.5° East longitude. This longitude passes through the city of Allahabad in Uttar Pradesh, India.

IST was first adopted in 1884 by the British Raj, and it has been in use ever since. It is the official time zone for all of India, except for the Andaman and Nicobar Islands, which use UTC+06:30.

IST is also used in some other countries in the Indian subcontinent, including Nepal, Bhutan, and Sri Lanka.