Convert JST to EST
To convert JST to EST: 10:00 AM JST is 8:00 PM EST the previous day. JST is UTC+09:00 and EST is UTC-05:00, so EST is 14 hours behind JST, but not all year, as explained below.
In Eastern Standard Time
- 10:00 AM JST
- 8:00 PM EST (previous day)
- On a 24-hour clock
- 10:00 JST is 20:00 EST
- The offsets
- JST is UTC+09:00, EST is UTC-05:00
- Difference
- EST is 14 hours behind JST
- Date
- The previous day. Going back 14 hours crosses midnight from this time.
- This gap does NOT hold all year Convert through the offset in force on the date you care about.
- The two ends switch on different dates, or one does not switch at all.
- EST is only in force part of the year United States: daylight time starts the second Sunday in March, at 02:00 local time and ends the first Sunday in November, at 02:00 local time (Energy Policy Act of 2005, in force since 2007). In 2026 that is 2026-03-08 to 2026-11-01. New York is on EDT between those dates.
- otherwise EDT, UTC-04:00
- Military time zone letters Z (Zulu) is UTC. A to M run east of Greenwich an hour apart, N to Y west, and J is left out. A letter names an offset, so a zone that switches to daylight time changes letter: EST is R, EDT is Q.
- JST is I (India), EST is R (Romeo)
- In every zone
- HST 15:00 AKST 16:00 PST 17:00 AKDT 17:00 MST 18:00 PDT 18:00 CST 19:00 MDT 19:00 EST 20:00 CDT 20:00 EDT 21:00 UTC 01:00 GMT 01:00 BST 02:00 CET 02:00 CEST 03:00 EET 03:00 EEST 04:00 MSK 04:00 IST 06:30 SGT 09:00 HKT 09:00 JST 10:00 AEST 11:00 AEDT 12:00 NZST 13:00 NZDT 14:00
How the Time Zone Converter works
Japan Standard Time (JST) is UTC+09:00 and Eastern Standard Time (EST) is UTC-05:00, so converting JST to EST means subtracting 14 hours from the JST time. EST is 14 hours behind JST.
Worked through: 10:00 AM JST is 8:00 PM EST the previous day. Note the date: this pair crosses midnight for much of the day, so the answer is often a different day as well as a different time. The day is the part a conversion done in your head tends to drop.
The gap between these two is not the same all year, which is the thing to get right. JST never shifts and EST does, so the difference moves. Convert through the offset in force on the date you care about rather than through the abbreviation somebody typed; the offsets above are definitions and the abbreviation is a claim about the calendar.
Fourteen hours back in winter and thirteen in summer, which makes Tokyo and New York almost exactly half a day apart, so this conversion nearly always changes the date. 10:00 on a Tuesday in Tokyo is 20:00 on Monday in New York. Japan has no daylight saving, so once again the entire seasonal variation comes from the American end: the gap shrinks by an hour in March without anything in Japan changing.
One thing worth stating plainly, because it is the most common mistake in this whole subject: an abbreviation is not a place. JST is fixed, so it is the same all year. EST is likewise only in force for part of the year in New York; otherwise it is EDT at UTC-04:00. If what you have is a city and a date rather than a pair of abbreviations, that is a different question and needs the tz database, not arithmetic. This is also why the shifting designations exist: ET means Eastern time whichever of the two is in force. Searching for ET and searching for JST to EST are the same question in two vocabularies, which is why this converter answers both.
Common times for this pair:
- 9:00 AM JST is 7:00 PM EST the previous day - 10:00 AM JST is 8:00 PM EST the previous day - 3:00 PM JST is 1:00 AM EST - 6:00 PM JST is 4:00 AM EST
Time Zone Converter FAQ
What is the time difference between JST and EST?
EST is 14 hours behind JST. JST is UTC+09:00 and EST is UTC-05:00, and both offsets are definitions rather than measurements, so the subtraction is exact.
What time is 10:00 AM JST in EST?
10:00 AM JST is 8:00 PM EST the previous day. Subtract 14 hours and carry the date if it crosses midnight.
Does the difference between JST and EST change with daylight saving?
Yes, and this is the main thing to watch on this pair. JST is fixed and EST shifts by an hour for part of the year, so the difference takes more than one value across the year. In 2026 the United States switch runs from 2026-03-08 to 2026-11-01.
Is there anything specific to this pair worth knowing?
Fourteen hours back in winter and thirteen in summer, which makes Tokyo and New York almost exactly half a day apart, so this conversion nearly always changes the date. 10:00 on a Tuesday in Tokyo is 20:00 on Monday in New York. Japan has no daylight saving, so once again the entire seasonal variation comes from the American end: the gap shrinks by an hour in March without anything in Japan changing.
Someone wrote EST but it is summer. What do they mean?
Almost certainly the zone rather than the abbreviation: New York time, which in summer is EDT at UTC-04:00 rather than EST at UTC-05:00. People type the standard-time abbreviation all year round. If an invitation is an hour out from what you calculated, this is why.