JST to GMT Converter & Meeting Planner
Quick answer: 9:00 AM JST = 12:00 AM GMT (fixed +09:00 standard offset — not DST-adjusted). Use the interactive converter below for DST-aware local-time scheduling.
Planning a call or meeting between Japan Standard Time (JST) and Greenwich Mean Time (GMT)? You need to account for the standard time difference. Greenwich Mean Time is normally 9 hours behind Japan Standard Time. Whether you are coordinating between teams in Tokyo and Osaka and London and Dublin, our live tool has you covered. Use our interactive overlap studio below to find the perfect waking hours for both regions, taking into account any seasonal Daylight Saving Time (DST) changes.
24-Hour Conversion Table
Quick reference: 12:00 AM JST = 3:00 PM GMT. The full 24-hour JST to GMT table below uses fixed standard offsets for exact abbreviation searches.
Example: 3:00 PM JST = 6:00 AM GMT.
| JST Time | GMT Time |
|---|---|
| 12:00 AM (00:00) | 3:00 PM (15:00)-1 day |
| 1:00 AM (01:00) | 4:00 PM (16:00)-1 day |
| 2:00 AM (02:00) | 5:00 PM (17:00)-1 day |
| 3:00 AM (03:00) | 6:00 PM (18:00)-1 day |
| 4:00 AM (04:00) | 7:00 PM (19:00)-1 day |
| 5:00 AM (05:00) | 8:00 PM (20:00)-1 day |
| 6:00 AM (06:00) | 9:00 PM (21:00)-1 day |
| 7:00 AM (07:00) | 10:00 PM (22:00)-1 day |
| 8:00 AM (08:00) | 11:00 PM (23:00)-1 day |
| 9:00 AM (09:00) | 12:00 AM (00:00) |
| 10:00 AM (10:00) | 1:00 AM (01:00) |
| 11:00 AM (11:00) | 2:00 AM (02:00) |
| 12:00 PM (12:00) | 3:00 AM (03:00) |
| 1:00 PM (13:00) | 4:00 AM (04:00) |
| 2:00 PM (14:00) | 5:00 AM (05:00) |
| 3:00 PM (15:00) | 6:00 AM (06:00) |
| 4:00 PM (16:00) | 7:00 AM (07:00) |
| 5:00 PM (17:00) | 8:00 AM (08:00) |
| 6:00 PM (18:00) | 9:00 AM (09:00) |
| 7:00 PM (19:00) | 10:00 AM (10:00) |
| 8:00 PM (20:00) | 11:00 AM (11:00) |
| 9:00 PM (21:00) | 12:00 PM (12:00) |
| 10:00 PM (22:00) | 1:00 PM (13:00) |
| 11:00 PM (23:00) | 2:00 PM (14:00) |
Best time to call London from Tokyo
For most work calls, compare the normal business day in Tokyo (JST) with the business day in London (GMT). JST commonly covers East Asia, while GMT is mainly associated with Europe, Africa.
⚠️ Note: 2026-07-05 is not a normal workday in one or both regions based on their configured calendar. The overlap below should be treated as a reference, not a guaranteed office-hours window.
✅ The most practical overlap on 2026-07-05 is usually 5:00 PM - 6:00 PM JST, which corresponds to 9:00 AM - 10:00 AM GMT. This window sits inside the typical JST workday (9:00 AM - 6:00 PM) and the GMT workday (9:00 AM - 5:00 PM).
- DST Safety: JST or GMT may shift during Daylight Saving Time. Always confirm the converted time for your specific date.
- Tokyo Stock Exchange (TSE): 09:00-15:00 local time in Tokyo.
- London Stock Exchange: 08:00-16:30 local time in London.
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Frequently Asked Questions
What is the time difference between JST and GMT?
During standard time, Greenwich Mean Time is 9 hours behind Japan Standard Time.
Does Japan observe Daylight Saving Time?
Japan has not observed Daylight Saving Time since 1951, when the practice introduced during the Allied occupation was abolished by the Japanese government. JST has remained fixed at UTC+9:00 ever since, and there is no current legislation to reintroduce DST in Japan.
Is JST the same as Korean Standard Time (KST)?
Yes, South Korea's Korean Standard Time (KST) operates at the same UTC+9:00 offset as JST, and South Korea also does not observe Daylight Saving Time. The two countries share an identical clock year-round, which simplifies scheduling for the significant trade, technology, and cultural exchange between Tokyo and Seoul.
What is the difference between GMT and BST?
GMT (Greenwich Mean Time) is the UK's standard winter offset at UTC+0, observed from the last Sunday in October through the last Sunday in March. BST (British Summer Time) is the daylight saving offset at UTC+1, applied each summer when clocks advance one hour.
Is GMT the same as UTC?
GMT and UTC share exactly the same numerical offset — both represent UTC+00:00 — but they are fundamentally different in nature. UTC is an atomic-clock-based international time standard used as the global reference, while GMT is a geographic time zone legally observed by specific countries including the United Kingdom and Ireland during winter months.