JST to GMT Converter
GMT is 9 hours behind JST
JST to GMT Conversion Table
Green rows indicate standard business hours (9 AM – 5 PM) in GMT
| JST | GMT |
|---|---|
| 12:00 AM | 3:00 PM -1d |
| 1:00 AM | 4:00 PM -1d |
| 2:00 AM | 5:00 PM -1d |
| 3:00 AM | 6:00 PM -1d |
| 4:00 AM | 7:00 PM -1d |
| 5:00 AM | 8:00 PM -1d |
| 6:00 AM | 9:00 PM -1d |
| 7:00 AM | 10:00 PM -1d |
| 8:00 AM | 11:00 PM -1d |
| 9:00 AM | 12:00 AM |
| 10:00 AM | 1:00 AM |
| 11:00 AM | 2:00 AM |
| 12:00 PM | 3:00 AM |
| 1:00 PM | 4:00 AM |
| 2:00 PM | 5:00 AM |
| 3:00 PM | 6:00 AM |
| 4:00 PM | 7:00 AM |
| 5:00 PM | 8:00 AM |
| 6:00 PM | 9:00 AM |
| 7:00 PM | 10:00 AM |
| 8:00 PM | 11:00 AM |
| 9:00 PM | 12:00 PM |
| 10:00 PM | 1:00 PM |
| 11:00 PM | 2:00 PM |
Converting Japan Standard Time to Greenwich Mean Time
Japan Standard Time (JST) and Greenwich Mean Time (GMT) are separated by a 9 hours time difference. GMT is 9 hours behind JST. JST is UTC+9, used in Japan, while GMT is UTC+0, used in United Kingdom, Ireland, Portugal.
When converting from JST to GMT, the key reference points to remember are: 9:00 AM JST equals 12:00 AM GMT, 12:00 PM noon JST equals 3:00 AM GMT, and 5:00 PM JST equals 8:00 AM GMT. The conversion table above shows every hour of the day mapped between these two time zones.
Scheduling Across JST and GMT
For professionals scheduling meetings between JST and GMT, finding overlapping business hours is essential. Standard business hours are typically 9:00 AM to 5:00 PM in each time zone. Given the 9 hours difference, the window of overlap may be limited, making early morning or late evening calls necessary for one party. Use the highlighted working hours in the conversion table above to quickly identify suitable meeting times.
Daylight Saving Time Considerations
JST does not observe Daylight Saving Time, maintaining UTC+9 year-round. GMT observes DST, switching to BST (UTC+1). During DST transitions, the time difference between these zones may temporarily change by 1 hour. Always verify the current offset during spring and fall transition periods.