Convert JST to GMT

Japan Standard Time (JST) to Greenwich Mean Time (GMT)

Japanese corporations with UK and European operations -- spanning automotive (Toyota Derbyshire plant, Nissan Sunderland plant), finance (Nomura, Daiwa London offices), and technology partnerships -- convert JST to GMT for board calls, market handoffs, and cross-regional standups. The 9-hour gap means Tokyo mornings catch London's previous evening, and the only productive overlap is when Tokyo stays late or London starts early.

When it's 12:00 PM in Tokyo, it's 3:00 AM GMT

JST UTC+9 GMT UTC±0 -9h

Interactive Converter

Pick any time and date to convert between JST and GMT.

JST to GMT Conversion Table

Full 24-hour comparison. Business hours (9 AM -- 6 PM) are highlighted.

Tokyo (JST)	GMT (GMT)
12:00 AM	3:00 PM -1 day
1:00 AM	4:00 PM -1 day
2:00 AM	5:00 PM -1 day
3:00 AM	6:00 PM -1 day
4:00 AM	7:00 PM -1 day
5:00 AM	8:00 PM -1 day
6:00 AM	9:00 PM -1 day
7:00 AM	10:00 PM -1 day
8:00 AM	11:00 PM -1 day
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

Best Meeting Window

Top meeting times for teams in JST and GMT (9 AM -- 6 PM work hours, 1-hour meeting).

12a

12p

Tokyo

GMT

Overlap

Everyone available

Most available

Some overlap

Outside work hours

1 1:00 PM -- 2:00 PM in Tokyo

Tokyo: 1:00 PM GMT: 4:00 AM

1 of 2 members within working hours. 1 in mid-day range (9 AM–5 PM). Outside work hours for GMT.

5.9 / 10

2 2:00 PM -- 3:00 PM in Tokyo

Tokyo: 2:00 PM GMT: 5:00 AM

1 of 2 members within working hours. 1 in mid-day range (9 AM–5 PM). Outside work hours for GMT.

5.9 / 10

3 9:00 PM -- 10:00 PM in Tokyo

Tokyo: 9:00 PM GMT: 12:00 PM

1 of 2 members within working hours. 1 in mid-day range (9 AM–5 PM). Outside work hours for Tokyo.

5.9 / 10

Try the Meeting Planner with custom work hours →

Scheduling Tips

Schedule meetings at 5:00-6:00 PM JST / 8:00-9:00 AM GMT to catch both teams during or near working hours.
During BST (late March to late October), the overlap improves to 4:00-6:00 PM JST / 8:00-10:00 AM BST -- use the wider window for longer discussions.
For async handoffs, have the Tokyo team post updates before 6:00 PM JST so London sees them at 9:00 AM GMT the same day.

Time Difference & DST

GMT is 9 hours behind JST all year.

Dates	Tokyo	GMT	Difference
Jan 1, 2026 – Dec 31, 2027	UTC+9	UTC±0	-9h

Tokyo, GMT do not use daylight saving time.

UK clocks use BST (UTC+1) from the last Sunday in March to the last Sunday in October.

Use the interactive converter for a specific date.

Major Cities

Japan Standard Time (JST)

Tokyo
Osaka
Yokohama

Greenwich Mean Time (GMT)

Frequently Asked Questions

What is the time difference between JST and GMT?

JST (Japan Standard Time, UTC+9) is 9 hours ahead of GMT (UTC+0) all year. When it is 5:00 PM in Tokyo, it is 8:00 AM GMT. UK clocks use BST (UTC+1) from late March to late October, so London is 8 hours behind Tokyo in summer.

What is 9:00 AM JST in London time?

9:00 AM JST is 12:00 AM (midnight) GMT. During BST (summer), 9:00 AM JST is 1:00 AM BST. Japanese mornings fall entirely outside UK business hours.

When is the best time for a call from Tokyo to London?

The most practical window is 5:00-6:00 PM JST / 8:00-9:00 AM GMT. Tokyo colleagues stay slightly past core hours to catch the London morning. During BST, this improves to 4:00-6:00 PM JST / 8:00-10:00 AM BST, giving a full 2-hour window.

Does Japan observe daylight saving time?

No. Japan uses JST (UTC+9) year-round. The only seasonal change in the Tokyo-London offset comes from the UK side when it switches to BST (UTC+1), reducing the gap from 9 to 8 hours.