IST to EST converter
Eastern Time is 10 hours 30 minutes behind India Standard Time in winter (EST, UTC−5) and 9 hours 30 minutes behind in summer (EDT, UTC−4). To convert IST to EST, subtract 10 hours 30 minutes during standard time and 9 hours 30 minutes during daylight saving time.
India Standard Time runs at UTC+5:30, Eastern Time at UTC−5 / UTC−4.
IST to EST conversion table
Every hour of the day converted for both halves of the year. The two columns differ because Eastern Time changes its offset for daylight saving time.
| India Standard Time (IST) | EST (Nov–Mar) | EDT (Mar–Nov) |
|---|---|---|
| 00:00 12:00 AM | 13:30 1:30 PM previous day | 14:30 2:30 PM previous day |
| 01:00 1:00 AM | 14:30 2:30 PM previous day | 15:30 3:30 PM previous day |
| 02:00 2:00 AM | 15:30 3:30 PM previous day | 16:30 4:30 PM previous day |
| 03:00 3:00 AM | 16:30 4:30 PM previous day | 17:30 5:30 PM previous day |
| 04:00 4:00 AM | 17:30 5:30 PM previous day | 18:30 6:30 PM previous day |
| 05:00 5:00 AM | 18:30 6:30 PM previous day | 19:30 7:30 PM previous day |
| 06:00 6:00 AM | 19:30 7:30 PM previous day | 20:30 8:30 PM previous day |
| 07:00 7:00 AM | 20:30 8:30 PM previous day | 21:30 9:30 PM previous day |
| 08:00 8:00 AM | 21:30 9:30 PM previous day | 22:30 10:30 PM previous day |
| 09:00 9:00 AM | 22:30 10:30 PM previous day | 23:30 11:30 PM previous day |
| 10:00 10:00 AM | 23:30 11:30 PM previous day | 00:30 12:30 AM |
| 11:00 11:00 AM | 00:30 12:30 AM | 01:30 1:30 AM |
| 12:00 12:00 PM | 01:30 1:30 AM | 02:30 2:30 AM |
| 13:00 1:00 PM | 02:30 2:30 AM | 03:30 3:30 AM |
| 14:00 2:00 PM | 03:30 3:30 AM | 04:30 4:30 AM |
| 15:00 3:00 PM | 04:30 4:30 AM | 05:30 5:30 AM |
| 16:00 4:00 PM | 05:30 5:30 AM | 06:30 6:30 AM |
| 17:00 5:00 PM | 06:30 6:30 AM | 07:30 7:30 AM |
| 18:00 6:00 PM | 07:30 7:30 AM | 08:30 8:30 AM |
| 19:00 7:00 PM | 08:30 8:30 AM | 09:30 9:30 AM |
| 20:00 8:00 PM | 09:30 9:30 AM | 10:30 10:30 AM |
| 21:00 9:00 PM | 10:30 10:30 AM | 11:30 11:30 AM |
| 22:00 10:00 PM | 11:30 11:30 AM | 12:30 12:30 PM |
| 23:00 11:00 PM | 12:30 12:30 PM | 13:30 1:30 PM |
How the IST to EST conversion works
Converting IST to EST means taking a wall-clock time in India Standard Time (IST, UTC+5:30) and expressing the same instant in Eastern Time (EST / EDT, UTC−5 / UTC−4). The arithmetic is one step: subtract 10 hours 30 minutes while Eastern Time is on standard time, and 9 hours 30 minutes while it is on daylight saving time. Applying the gap pushes part of the day onto a different calendar date — the table below marks every row that shifts. In code, store the instant in UTC and convert with the IANA identifiers Asia/Kolkata and America/New_York, never with the abbreviations. One note on the source label: IST is also used for Irish Standard Time and Israel Standard Time, so the abbreviation alone is ambiguous. On the target label: EST is also used for Australian Eastern Standard Time (UTC+10), so the abbreviation alone is ambiguous.
Best time for meetings between IST and EST
Working hours are taken as 09:00–18:00 in each zone. The window in force depends on the date, so both halves of the year are listed where they differ.
EST (Nov–Mar)
A 9-to-6 working day in the two zones does not overlap at all. The EST working day runs from 7:30 PM to 4:30 AM the next day in IST terms, so a shared call means an early start on one side or a late finish on the other.
EDT (Mar–Nov)
A 9-to-6 working day in the two zones does not overlap at all. The EDT working day runs from 6:30 PM to 3:30 AM the next day in IST terms, so a shared call still costs one side an early morning or a late evening.
Daylight saving time: which side moves
Only Eastern Time shifts. India Standard Time holds a single offset all year, so every change in the gap comes from Eastern Time moving between EST (UTC−5) and EDT (UTC−4).
Eastern Time is 10 hours 30 minutes behind India Standard Time through the Nov–Mar window, and 9 hours 30 minutes behind through the Mar–Nov window.
US daylight saving time runs from the second Sunday in March to the first Sunday in November.
- India Standard Time
- Asia/Kolkata
- IST — UTC+5:30
- Eastern Time
- America/New_York
- EST / EDT — UTC−5 / UTC−4
Frequently asked questions
What is the time difference between IST and EST?
Eastern Time runs 10 hours 30 minutes behind India Standard Time during standard time and 9 hours 30 minutes behind during daylight saving time. In offset terms, India Standard Time sits at UTC+5:30 and Eastern Time at UTC−5 / UTC−4. So 9:00 AM IST is 10:30 PM the previous day EST, and 11:30 PM the previous day EDT once the clocks change.
Does the IST to EST difference change with daylight saving time?
The difference does change. Eastern Time moves its clocks, so the gap swings between 10 hours 30 minutes and 9 hours 30 minutes depending on the date. In the US that means clocks move forward on the second Sunday of March and back on the first Sunday of November. Convert against the IANA rules for the exact date rather than a remembered offset.
What time is 9 am IST in EST?
9:00 AM IST is 10:30 PM the previous day in Eastern Time during standard time (EST) and 11:30 PM the previous day during daylight saving time (EDT). The rule is the same one the whole page runs on: subtract 10 hours 30 minutes in winter and 9 hours 30 minutes in summer.
What do IST and EST stand for?
IST stands for India Standard Time. EST stands for Eastern Standard Time, and EDT is Eastern Daylight Time. Both are display labels rather than rules: the offsets behind them come from the IANA identifiers Asia/Kolkata and America/New_York. IST is also used for Irish Standard Time and Israel Standard Time, so the abbreviation alone is ambiguous.
Related conversions
Need more than two zones at once? The full timezone converter shows a single moment across up to six IANA timezones, for any date you choose.