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GMT to JST Time Converter

Use this GMT to JST time converter to compare United Kingdom and Japan time instantly. JST is 9 hours ahead of GMT, so 9:00 AM GMT becomes 6:00 PM JST and 5:00 PM GMT becomes 2:00 AM (next day) JST. The page is useful for business-hours overlap, international calls, remote-team handoffs, webinars, and travel planning, with daylight saving adjustments handled automatically.

GMT Greenwich Mean Time
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JST Japan Standard Time
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Select a time to convert

GMT to JST Quick Facts

Use this GMT to JST converter to compare United Kingdom and Japan time, check the 9 hours gap, and confirm the right slot for calls, handoffs, and deadlines. Good overlap starts around 9:00 AM GMT / 6:00 PM JST.

Time Difference
Japan Standard Time is 9 hours ahead of Greenwich Mean Time
Useful when deadlines, handoffs, or calls cross workday boundaries.
Best Call Window
Best overlap starts around 9:00 AM GMT and 6:00 PM JST.
Common Use Cases
Useful for remote teams, customer support windows, travel planning, webinars, and same-day deadline handoffs.

How to Convert GMT to JST

Converting between Greenwich Mean Time and Japan Standard Time means accounting for a 9 hours gap — here's how to do it in under 10 seconds with no sign-up.

Enter Your GMT Time

Pick the date and time in Greenwich Mean Time (UTC +0) that you want to convert. Hit "Now" to load the current GMT time instantly, or use "+1h" to step forward and compare.

Read the JST Result

The equivalent Japan Standard Time (UTC +9) time appears immediately. Since JST is 9 hours ahead of GMT, most daytime conversions stay on the same calendar day.

Copy or Fine-Tune

Click "Copy Time" to grab the JST result for your calendar or message. Use "+1d" to check how the conversion shifts across dates — helpful for scheduling recurring Universal–Japan calls.

Why Choose Our GMT to JST Converter

Align GMT–JST Meetings Instantly

When someone in Universal suggests 9:00 AM GMT, that's 6:00 PM JST. This converter shows the overlap so both sides agree on one slot — no back-and-forth.

Spot Date-Line Shifts at a Glance

Late-night GMT times can land on a different date in JST because of the 9 hours offset. The converter labels "next day" or "previous day" next to the result so you never send a message a day early or miss a deadline.

Handles DST Transitions Automatically

Daylight Saving adjustments can widen or narrow the GMT–JST gap by an hour. During transition weeks many people get it wrong. This converter pulls the current UTC offsets automatically, so the result is right even on the changeover day.

Never Miss a GMT-Timed Event

Product launches, sports matches, and webinars are often announced in GMT. Convert the event time to JST so you know exactly when to tune in — with a 9 hours difference, a morning event in Universal falls during work hours in Japan.

GMT to JST Time Conversion Chart

Quick-reference conversion table covering every hour of the day at a glance.

Complete 24-Hour Conversion

Greenwich Mean Time to Japan Standard Time full day schedule

12:00 AM
GMT
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9:00 AM
JST
1:00 AM
GMT
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10:00 AM
JST
2:00 AM
GMT
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11:00 AM
JST
3:00 AM
GMT
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12:00 PM
JST
4:00 AM
GMT
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1:00 PM
JST
5:00 AM
GMT
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2:00 PM
JST
6:00 AM
GMT
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3:00 PM
JST
7:00 AM
GMT
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4:00 PM
JST
8:00 AM
GMT
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5:00 PM
JST
9:00 AM
GMT
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6:00 PM
JST
10:00 AM
GMT
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7:00 PM
JST
11:00 AM
GMT
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8:00 PM
JST
12:00 PM
GMT
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9:00 PM
JST
1:00 PM
GMT
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10:00 PM
JST
2:00 PM
GMT
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11:00 PM
JST
3:00 PM
GMT
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12:00 AM
JST
(next day)
4:00 PM
GMT
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1:00 AM
JST
(next day)
5:00 PM
GMT
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2:00 AM
JST
(next day)
6:00 PM
GMT
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3:00 AM
JST
(next day)
7:00 PM
GMT
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4:00 AM
JST
(next day)
8:00 PM
GMT
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5:00 AM
JST
(next day)
9:00 PM
GMT
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6:00 AM
JST
(next day)
10:00 PM
GMT
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7:00 AM
JST
(next day)
11:00 PM
GMT
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8:00 AM
JST
(next day)
The two zones in context

GMT vs JST — cities and working rhythm

GMT — Greenwich Mean Time
Primary cities: London, Dublin, Lisbon, Accra, Reykjavík

UK / Ireland / Iceland / Portugal / West Africa. Business hours 9 AM – 5:30 PM GMT typically. Note: London is on GMT in winter, BST (GMT+1) in summer — but "GMT" gets used loosely all year in scheduling contexts. Financial-services London anchors the European trading day.

JST — Japan Standard Time
Primary cities: Tokyo, Osaka, Sapporo, Nagoya, Fukuoka

Japan — one of the few large economies that has no DST, so JST is JST year-round (UTC+9). Business hours 9 AM – 6 PM JST with strong presence-based culture (staying past 7 PM is common). Same offset as Korean Standard Time (KST).

Time gap: JST is 9.0 hours ahead of GMT (standard-time offsets — daylight-saving flips shift this by an hour twice a year in most northern-hemisphere zones).

GMT to JST Time Difference, Business Hours, and DST

GMT to JST is one of the more useful timezone conversions for calls, deadlines, and travel planning. The current gap is 9 hours, which means 9:00 AM GMT becomes 6:00 PM JST and 2:00 PM GMT becomes 11:00 PM JST.

This matters when teams in London and Tokyo need to align business hours, webinars, or customer-support coverage. Use the chart on this page when you want the exact conversion for today instead of relying on manual offset math.

Daylight saving changes can also shift the gap during the year, so a converter is safer than memorizing a fixed difference. That is especially important for recurring meetings and date-sensitive handoffs.

GMT to JST FAQ

Quick answers about daylight saving time, date changes, business-hour overlap, and the most common scheduling questions between Greenwich Mean Time and Japan Standard Time.

What is the time difference between GMT and JST?

JST is 9 hours ahead of GMT. GMT is UTC +0:00 and JST is UTC +9:00 relative to UTC. Neither GMT nor JST observes daylight saving time, so the 9 hours gap stays constant all year. That makes scheduling between them predictable.

When can GMT and JST have business-hour overlap?

There is no clean business-hour overlap between GMT and JST — the 9 hours gap pushes at least one side outside 9-to-5. Schedule calls at the very start or end of one party's day.

Does GMT or JST observe daylight saving time?

Neither GMT nor JST observes daylight saving time, so the 9 hours gap stays constant all year. That makes scheduling between them predictable.

How do I quickly convert GMT to JST?

To convert GMT to JST, add 9 hours to the GMT time. Example: if it's 10:00 AM GMT, it's 19:00 JST that day. The live converter at the top of this page handles DST automatically.

Why convert GMT to JST?

UK/EU companies with Japanese partners or subsidiaries coordinate across this 9-hour gap (8 in BST). Automotive, electronics, gaming, and finance flows constantly between London and Tokyo.

When can London and Tokyo both be at work?

Tokyo morning ↔ London middle-of-night-then-early-morning is the only overlap. Practical window: 4:00-6:00 PM JST = 7:00-9:00 AM GMT (8:00-10:00 AM BST). Tokyo afternoon, London first thing.

Does Japan ever shift its time zone?

No. Japan has been on JST (UTC+9) year-round with no DST since 1952. When the UK moves to BST in summer, the gap to Tokyo shrinks from 9 to 8 hours.

Popular GMT Time Converters

Explore more GMT conversions for major business and travel corridors. Each page includes a 24-hour chart, time difference summary, and meeting overlap guidance.

Convert Other Time Zones to JST

Find the time difference from any major zone into Japan Standard Time. Use these pages when scheduling with Japan from a different region.

🇯🇵 Swap direction — JST to GMT Converter