India Time Converter (IST to US Zones)

The model, stated exactly

India Standard Time is UTC+5:30, one time zone for the whole country, with no daylight saving at any time of year. The live conversion never uses a hardcoded offset: it resolves the India wall time to an exact UTC instant through Intl.DateTimeFormat with timeZone Asia/Kolkata, then reads every US zone from that same instant with Intl, so US daylight saving is handled correctly for the date you enter. UTC time = India time minus 5 hours 30 minutes. US Eastern, Central, Mountain, and Pacific times are then whatever the real zone rules say for that instant — EDT or EST, CDT or CST, MDT or MST, PDT or PST — which is why the same India time maps to different US times in summer and winter.

The worked example, line by line

Setup: 12:00 India time on October 24, 2026.

Line 1 — UTC. 12:00 minus 5:30 = 06:30 UTC on October 24, 2026.

Line 2 — Eastern. UTC minus 4 hours (EDT, daylight saving) = 02:30 EDT on October 24, 2026.

Line 3 — Central. UTC minus 5 hours (CDT) = 01:30 CDT on October 24, 2026.

Line 4 — Mountain. UTC minus 6 hours (MDT) = 00:30 MDT on October 24, 2026.

Line 5 — Pacific. UTC minus 7 hours (PDT) = 23:30 PDT on October 23, 2026 — the previous day.

Try these

Winter: 12:00 IST on January 15, 2027. The UTC time is still 06:30 UTC, but the US has left daylight saving, so the same noon in India is 01:30 EST Eastern (Jan 15), 00:30 CST Central (Jan 15), 23:30 MST Mountain (Jan 14), and 22:30 PST Pacific (Jan 14). The India side never moves; the US side moves an hour with the seasons.

Evening in India, morning in the US. 21:00 IST on October 24, 2026 is 15:30 UTC, which is 11:30 EDT, 10:30 CDT, 09:30 MDT, and 08:30 PDT — the overlap window where both sides are awake, and the reason most India–US calls land in India's evening.

Midnight in India. 00:00 IST on October 24, 2026 is 18:30 UTC on October 23, which is 14:30 EDT, 13:30 CDT, 12:30 MDT, and 11:30 PDT on October 23 — a full calendar day behind on the US side for the Pacific zone.

Why the half hour exists

India's half-hour offset comes from geography: the country's standard meridian runs through Mirzapur in Uttar Pradesh, at 82.5° east, and each 15° of longitude is one hour of solar time — 82.5 ÷ 15 = 5.5 hours. A whole-hour zone would have put either the far east or the far west of India badly out of step with the sun, so the single national zone split the difference at the half hour. The practical consequence is the one this page exists for: any converter, mental shortcut, or scheduling tool that assumes whole-hour offsets gets India wrong by thirty minutes, every time. Trust the :30, and check the date on the US side separately, because it is usually a day behind.

Output · formula · meaning

Who uses this

• The manager scheduling a call with a team in India: enters noon IST and learns it is 02:30 EDT — then picks an India evening slot instead, where both sides are awake.
• The family calling relatives in India: enters the India time they were given and reads the US time and date, so nobody calls at 2 in the morning by mistake.
• The freelancer with clients in India: enters a deadline given in IST and reads the exact US deadline, including whether it falls on the previous US day.
• The traveler landing in India: enters the arrival time in IST and reads what time it is back home, so the first message home goes out at a civilized hour.

Accuracy & limitations

The conversion is exact for the date and time you enter, because it reads real time-zone data rather than a fixed offset table: India has no daylight saving, so the India side never shifts, while the US side follows the daylight saving rules in force on the date you enter. Two cautions remain. First, the US daylight saving rules themselves are law, not astronomy: if a future law changed them, conversions for dates after the change would follow the new rules, which is exactly why the live conversion reads zone data instead of hardcoding offsets. Second, this page converts clock time only — it does not account for travel, flight durations, or local holidays. Error policy: missing, malformed, or nonexistent dates and times are reported as errors rather than calculated, so no result ever shows NaN.