Indian Standard Time (IST) is the time observed throughout India and Sri Lanka, with a time offset of UTC+05:30.
India does not observe Daylight Saving Time (DST) or other seasonal adjustments. In military and aviation time IST is designated E* (“Echo-Star”).
Indian Standard Time is calculated on the basis of 82.5° E longitude, in Shankargarh Fort, Mirzapur (25.15°N 82.58°E) (Allahabad district in the state of Uttar Pradesh) which is nearly on the corresponding longitude reference line.
In the timezone database it is represented by Asia/Kolkata.