This GMT to JST converter turns any time in Greenwich Mean Time (GMT) into Japan Standard Time (JST), using your device clock so daylight saving is applied automatically. JST is 9 hours ahead of GMT. GMT is UTC+0; JST is UTC+9.
GMT covers Accra, Dakar, London in winter; JST covers Tokyo, Osaka. Neither zone observes daylight saving time, so the difference is the same every day of the year.
GMT and JST UTC offsets
GMT
UTC+0
Greenwich Mean Time
No daylight saving time
JST
UTC+9
Japan Standard Time
No daylight saving time
GMT to JST conversion table
| GMT | JST |
|---|---|
| 12 am | 9 am |
| 3 am | 12 pm |
| 6 am | 3 pm |
| 8 am | 5 pm |
| 9 am | 6 pm |
| 10 am | 7 pm |
| 11 am | 8 pm |
| 12 pm | 9 pm |
| 1 pm | 10 pm |
| 2 pm | 11 pm |
| 3 pm | 12 amnext day |
| 4 pm | 1 amnext day |
| 5 pm | 2 amnext day |
| 6 pm | 3 amnext day |
| 8 pm | 5 amnext day |
| 10 pm | 7 amnext day |
Frequently asked questions
What is the time difference between GMT and JST?
JST is 9 hours ahead of GMT. That comes from the UTC offsets: GMT is UTC+0 and JST is UTC+9. For example, 9 am GMT = 6 pm JST.
Is JST ahead of or behind GMT?
JST is 9 hours ahead of GMT, so when it is noon in GMT it is 9 pm in JST. Ahead means the clock there already shows a later time; a call at 5 pm GMT lands at 2 am JST.
Does GMT or JST observe daylight saving time in 2026?
No. Neither GMT nor JST changes its clocks, so the 9 hours difference holds every day of the year. That makes recurring meetings between Accra and Tokyo easy to keep at a fixed local time on both ends.
What is the best time for a meeting between GMT and JST?
Office hours (9 am to 5 pm) do not overlap at all with a 9 hours difference. The least painful options are early morning in GMT or early evening in JST; for example 8 am GMT = 5 pm JST and 6 pm GMT = 3 am JST the next day. Rotate the inconvenient slot between the two sides for recurring calls.
Which cities use GMT and JST?
GMT (Greenwich Mean Time) is used in Accra, Dakar, London in winter. JST (Japan Standard Time) is used in Tokyo, Osaka. Note that the United Kingdom is only on GMT in winter; from late March to late October London runs on British Summer Time, one hour ahead, so use the BST pages for UK business hours in summer.