IST — India Standard Time

UTC+5:30 · No DST · Single time zone for all of India

IST — India Standard Time
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UTC+5:30No DST — Always UTC+5:30

IST Facts

UTC Offset
UTC+5:30
Abbreviation
IST
Full Name
India Standard Time
Daylight Saving
None — always UTC+5:30
IANA Identifier
Asia/Kolkata
Used By
All of India (one zone)

What Is IST Time in the USA?

IST is UTC+5:30. The US–India offset changes twice a year when the US observes Daylight Saving Time. India never changes.

US Time ZoneOffset from IST (winter)Offset from IST (summer)
EST (New York)-10:30 hrs-9:30 hrs
CST (Chicago)-11:30 hrs-10:30 hrs
MST (Denver)-12:30 hrs-11:30 hrs
PST (Los Angeles)-13:30 hrs-12:30 hrs

Example: When it is 12:00 PM IST, it is 1:30 AM EST (winter) or 2:30 AM EDT (summer).

Why Is India UTC+5:30 (30-Minute Offset)?

India uses a single time zone for the entire country — IST (UTC+5:30). The 30-minute offset was chosen as a compromise to cover India's geographic width (spanning roughly UTC+5 in the west to UTC+6 in the east).

India adopted a single national time zone in 1906 as a practical solution for unified railway and telegraph systems under British administration. The 5:30 offset was the midpoint between the extremes.

India does not observe Daylight Saving Time. IST is always UTC+5:30 year-round, every year. This means the time difference between India and the US, UK, or Europe changes when those countries switch clocks — not when India does.

Frequently Asked Questions

Where is the IST time zone?
IST (India Standard Time) is the time zone used across all of India. India is one of the few large countries to use a single national time zone rather than multiple zones. The IANA identifier is Asia/Kolkata. IST is UTC+5:30 and covers the entire Indian subcontinent including Sri Lanka does not use IST — Sri Lanka uses SLST (UTC+5:30, same offset but separate zone).
What is IST time in the USA?
IST (UTC+5:30) is far ahead of all US time zones. In winter: EST is 10.5 hours behind IST, CST is 11.5 hours behind, MST is 12.5 hours behind, PST is 13.5 hours behind. In summer (US DST active): EDT is 9.5 hours behind IST, CDT is 10.5 behind, MDT is 11.5 behind, PDT is 12.5 behind. Example: 12:00 PM IST = 1:30 AM EST in winter.
How do you convert IST to USA time?
To convert IST to EST (winter): subtract 10 hours and 30 minutes. To convert IST to EDT (summer): subtract 9 hours and 30 minutes. To convert IST to PST: subtract 13 hours and 30 minutes. To convert IST to PDT: subtract 12 hours and 30 minutes. Because India does not observe DST, the offset changes when the US clocks change, not when India's do.
Why does India have a 30-minute time zone offset?
India uses UTC+5:30 — a half-hour offset — as a compromise for the country's geographic width. India spans from roughly UTC+5 (western India) to UTC+6 (northeastern India). Rather than adopt two time zones or round to a full hour, India chose 5:30 as the midpoint when standardizing railway time in 1906. It remains one of the few countries with a 30-minute UTC offset.
Does India observe Daylight Saving Time?
No. India does not observe Daylight Saving Time. IST is always UTC+5:30, year-round, every year. This means the time difference between India and countries like the US, UK, and EU shifts twice a year when those countries change their clocks — India's clocks never move.
What is the difference between IST and GMT?
IST (India Standard Time) is UTC+5:30, which means India is 5 hours and 30 minutes ahead of GMT/UTC. When it is 12:00 PM GMT, it is 5:30 PM IST. During UK summer (BST, UTC+1), India is 4 hours and 30 minutes ahead of UK time.

IST Converters & Related Time Zones

IST to EST ConverterIST to PST ConverterIST to CST ConverterIST to GMT ConverterIndia Current TimeGMT Time NowUTC Time NowEST — Eastern Standard TimePST — Pacific Standard TimeTime Zone Converter
IST data sourced from IANA Time Zone Database (Asia/Kolkata). India Standard Time is UTC+5:30 permanently. India does not observe Daylight Saving Time.