IST time now (India Standard Time)

6:22PMIST

UTC+5:30+10 h 30 min vs New York (you)Kolkata now: IST, UTC+5:30

What IST means

IST stands for India Standard Time, UTC+5:30. It is used in India (and Sri Lanka on the same offset).

IST is ambiguous. It also means Israel Standard Time (UTC+2, Israel, in winter) and Irish Standard Time (UTC+1, Ireland, in summer). This page shows UTC+5:30, the meaning English searchers usually want.

IST means three different things

IST is the standard abbreviation of India Standard Time, UTC+5:30, the single time of all of India (Sri Lanka uses the same offset). The same letters are used for Israel Standard Time (UTC+2, in winter) and Irish Standard Time (UTC+1, Ireland’s summer time). tzdata uses IST for all three.

The spread is 3½ hours, enough to wreck a meeting. A message from Dublin in August saying “10:00 IST” means 09:00 UTC; the same text from Tel Aviv in January means 08:00 UTC, and from Bengaluru 04:30 UTC. When the context is not obvious, write UTC+5:30 or the city.

India Standard Time has stayed at UTC+5:30 without daylight saving time since 1945, according to tzdata. Israel changes clocks between IST and IDT (UTC+3) every year.

Where and when IST is used

1 zone uses IST all year. Computed from tzdata under the current rules.

Main cityTime zoneCountriesWhen
MumbaiAsia/KolkataIndiaall year

Other meanings of IST

MeaningOffsetWhereTime now there
India Standard TimeUTC+5:30India (and Sri Lanka on the same offset)6:22 PM
Israel Standard TimeUTC+2Israel, in winter (Jerusalem)2:52 PM IST
Irish Standard TimeUTC+1Ireland, in summer (Dublin)12:52 PM GMT

When a time arrives with only these letters, look at where the sender is, or ask for the UTC offset. Calendars and programs should never guess a zone from an abbreviation: the IANA database’s own documentation calls abbreviations ambiguous in practice.

How long IST has been used

In the tzdata record, Mumbai has used IST since 1905.

IST in the past

Zones whose tzdata history shows IST before 2025 but that no longer use it:

IST converted to other zones

Every column is a fixed offset, so this table is valid on any date. Remember that the regions behind some columns switch to summer time (EST to EDT, CET to CEST, GMT to BST); the clock in those cities is then an hour later than the column.

IST (UTC+5:30)UTC (UTC+0)EST (UTC−5)PST (UTC−8)CET (UTC+1)JST (UTC+9)AEST (UTC+10)CST (UTC−6)
12:00 AM6:30 PM (−1 day)1:30 PM (−1 day)10:30 AM (−1 day)7:30 PM (−1 day)3:30 AM4:30 AM12:30 PM (−1 day)
6:00 AM12:30 AM7:30 PM (−1 day)4:30 PM (−1 day)1:30 AM9:30 AM10:30 AM6:30 PM (−1 day)
9:00 AM3:30 AM10:30 PM (−1 day)7:30 PM (−1 day)4:30 AM12:30 PM1:30 PM9:30 PM (−1 day)
12:00 PM6:30 AM1:30 AM10:30 PM (−1 day)7:30 AM3:30 PM4:30 PM12:30 AM
3:00 PM9:30 AM4:30 AM1:30 AM10:30 AM6:30 PM7:30 PM3:30 AM
6:00 PM12:30 PM7:30 AM4:30 AM1:30 PM9:30 PM10:30 PM6:30 AM
9:00 PM3:30 PM10:30 AM7:30 AM4:30 PM12:30 AM (+1 day)1:30 AM (+1 day)9:30 AM

Questions

What is IST in UTC?
IST is UTC+5:30: 5 hours 30 minutes ahead of Coordinated Universal Time.
What does IST stand for?
India Standard Time. It can also mean Israel Standard Time or Irish Standard Time.
Which places use IST all year?
Mumbai.

Related zones and conversions