IST in one sentence
Indian Standard Time is the civil time used by India for clocks, travel, government work, banking, courts, media and everyday scheduling. If it is 12:00 UTC, the time in India is 5:30 PM IST.
Why India is UTC+5:30
India uses a standard meridian near 82.5 degrees east longitude. A full hour equals 15 degrees of longitude, so 82.5 degrees east corresponds to five and a half hours ahead of Greenwich or UTC. This is why India has the unusual half-hour offset used by many global calendars and devices.
Does India have daylight saving time?
No. India does not currently observe daylight saving time. This makes IST stable throughout the year, but it also means India's time difference with countries such as the United States and United Kingdom changes when those countries move into or out of daylight saving time.
IST, Asia/Kolkata and devices
Most computers and phones represent Indian time through the IANA timezone identifier Asia/Kolkata. Older systems may refer to Calcutta, but the practical offset is the same for modern civil time: UTC+5:30.
Useful next steps
Use the live IST clock for the current time, the IST converter for meeting planning, and India vs USA time if your schedule depends on daylight saving changes.
Common mistakes
IST can also mean Irish Standard Time or Israel Standard Time in other contexts. On IndiaTime.co.in, IST refers to Indian Standard Time unless a page explicitly says otherwise. For legal, aviation, market or cross-border work, always confirm the timezone label in the source system rather than relying only on the abbreviation.