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India Time Zone (IST) Explained

Indian Standard Time UTC+5:30 nationwide, no DST, and offsets vs major world cities.

All of India uses **Indian Standard Time** (IST) — IANA zone Asia/Kolkata, UTC+5:30, **no daylight saving**. Mumbai, Kolkata, Delhi, and Bangalore share the same official clock, unlike multi-zone countries such as the US or Russia.

Why UTC+5:30

After independence India unified on one half-hour offset for rail, broadcast, and administration. Never round IST to UTC+5 or UTC+6 — meetings slip by 30 minutes. See Half-Hour and Quarter-Hour Time Zones.

Common offsets

  • IST vs Beijing (UTC+8): Beijing is 2.5 hours ahead
  • IST vs London (UTC+0/+1): India is 4.5–5.5 hours ahead
  • IST vs New York (UTC-5/-4): India is 9.5–10.5 hours ahead
  • IST vs Dubai (UTC+4): India is 1.5 hours ahead

Tips

Schedule International Meetings with Asia/Kolkata in the Convert. BPO and support shifts often run on IST. Neighbor Nepal uses UTC+5:45 — do not mix them up. More in Guides.