Current IST Time

India Standard Time (IST)

IST (India Standard Time) is UTC+5:30. The half-hour offset is rare globally and a common source of bugs in scheduling software. India spans a wide longitude range but uses a single timezone for the entire country with no daylight saving time. The IANA timezone is Asia/Kolkata (formerly Asia/Calcutta).

Where India Standard Time is observed

IST (UTC+5:30) covers the entire territory of India and Sri Lanka. India is among the largest countries that use a single timezone end-to-end, with no daylight saving time. IANA: Asia/Kolkata.

• India: every city — Mumbai, Delhi, Bengaluru, Chennai, Kolkata, Hyderabad, Pune
• Sri Lanka also uses UTC+5:30 (Asia/Colombo), although it briefly shifted to UTC+6 in 2024
• India spans roughly 2,000 km east-to-west, so solar noon differs by ~2 hours within one IST clock
• The "+5:30" half-hour offset is unusual — most timezones are aligned on whole-hour offsets

No DST and the half-hour offset

India has not observed daylight saving since 1945. The +5:30 offset is a compromise between solar time at the eastern and western edges of the country, calibrated to the 82.5°E meridian. Two other notable IST collisions exist: Irish Standard Time (IST, UTC+1 in summer) and Israel Standard Time — always use Asia/Kolkata in code.

• Single nationwide offset since 1947
• No daylight saving since 1945
• Irish Standard Time and Israel Standard Time share the abbreviation IST — disambiguate with the IANA name

Convert IST to other timezones (IST to EST, IST to UTC, IST to PST)

Pairwise conversions for India Standard Time: convert IST to EST, IST to UTC, IST to PST. IST (UTC+5:30) is 10.5 hours ahead of EST and 13.5 hours ahead of PST in winter. The half-hour offset is a frequent source of off-by-30-minute bugs in international apps.

• Convert IST to EST / IST to EST time conversion — IST is 10.5 hours ahead of EST in winter; 21:30 IST = 11:00 EST
• IST to UTC — IST is 5.5 hours ahead of UTC; 17:30 IST = 12:00 UTC
• IST to PST — IST is 13.5 hours ahead of PST in winter; 22:30 IST = 09:00 PST
• IST to CST — IST is 11.5 hours ahead of US CST in winter
• IST never observes DST; the offset is constant at UTC+5:30 year-round

IST aliases: India Standard Time, EST↔IST calculator, 12 AM CST to IST

Common search phrasings for IST pairs: "est to india time converter", "12 am cst to ist", "cst ist conversion". IST is UTC+5:30 year-round with no DST, so cross-DST conversions need a winter/summer offset table.

• EST to India time converter / est to india time converter — IST = EST + 10:30 in winter; 12:00 EST = 22:30 IST
• 12 AM CST to IST / 12 am cst to ist — 00:00 CST (winter) = 11:30 IST; CST + 11:30 in winter, CST + 10:30 in summer (US DST)
• CST IST conversion / cst ist conversion — see /timezone/cst for the CST side of the same calculation
• IST = UTC+5:30 year-round, no DST

IST↔PST/EST: ist and pst time converter, ist time conversion to est, 12 PM PST to IST

More IST queries: "ist and pst time converter", "ist time conversion to est", "12 pm pst to ist", "7 am cst to ist".

• IST and PST time converter / ist and pst time converter — IST is 13:30 ahead of PST in US winter; 22:30 IST = 09:00 PST
• IST time conversion to EST / ist time conversion to est — IST is 10:30 ahead of EST in US winter; 22:30 IST = 12:00 EST
• 12 PM PST to IST / 12 pm pst to ist — 12:00 PST (winter) = 01:30 IST next day
• 7 AM CST to IST / 7 am cst to ist — 07:00 CST (winter) = 18:30 IST

India time zone conversion, IST time zone conversion, IST to EST

More IST queries: "india time zone conversion", "ist time zone conversion", "ist to est time zone converter".

• India time zone conversion / india time zone conversion — IST is UTC+5:30 year-round; convert any source to UTC then add 5:30
• IST time zone conversion / ist time zone conversion — same as above; IANA name Asia/Kolkata
• IST to EST time zone converter / ist to est time zone converter — IST − 10:30 = EST in US winter; IST − 9:30 = EDT in summer