Indian Standard Time (IST) was approved as the official time zone for India on September 1, 1947, by the Indian Government. IST is the time zone recognised across the whole country with a time offset of UTC+5.30. During the British Raj in 1884, India managed to have two time zones, Bombay time and Calcutta time. Dating back to the 4th century CE, the book ‘Surya Siddhanta’ states that India related to the beginning of a 24-hour day with the sunrise at the prime meridian moving through Ujjain.
The ancient Indian astrophysics divided the time measured from the onset of the sunrise into smaller time units comprising one prana (a time span of one breath which is 4 seconds). 15 breaths equalled a minute. Yet, throughout the history of India, there was no regulated time zone.
Most of the towns and cities in India supported their local time patron until the railway system was started in the 1850s which provided rise to an important need for a combined time zone. The British Raj considered the use of the current time zone in 1802. Today, Indian Standard Time (IST) is the only time zone observed in India. IST is forward of Greenwich Mean Time (GMT) by 5.30 hours.
When was the Indian Standard Time officially introduced?
The Indian Standard Time (IST) was originated in India on September 1, 1947, by the Indian Government of Independent India.