The World Clock Converter
Event Planner

JST to KST Time Converter

Compare JST and KST instantly. The clocks below stay in sync with the IANA time-zone database, so daylight-saving transitions are handled automatically for both Tokyo and Seoul.

Saturday, Jul 25
03:34
:19PM
Today
Saturday, Jul 25
03:34
:19PM
Today

24-Hour Comparison Timeline

Green = working hours · Yellow = early/late · Red = night

● Best window: 9 AM–5 PM (Tokyo)
🇯🇵Tokyo
9AM
10AM
11AM
12PM
1PM
2PM
3PM
4PM
5PM
6PM
7PM
8PM
9PM
10PM
11PM
12AM
1AM
2AM
3AM
4AM
5AM
6AM
7AM
8AM
🇰🇷Seoul
9AM
10AM
11AM
12PM
1PM
2PM
3PM
4PM
5PM
6PM
7PM
8PM
9PM
10PM
11PM
12AM
1AM
2AM
3AM
4AM
5AM
6AM
7AM
8AM

24-hour reference table

JST (Tokyo)KST (Seoul)
12:00 AM12:00 AM
01:00 AM01:00 AM
02:00 AM02:00 AM
03:00 AM03:00 AM
04:00 AM04:00 AM
05:00 AM05:00 AM
06:00 AM06:00 AM
07:00 AM07:00 AM
08:00 AM08:00 AM
09:00 AM09:00 AM
10:00 AM10:00 AM
11:00 AM11:00 AM
12:00 PM12:00 PM
01:00 PM01:00 PM
02:00 PM02:00 PM
03:00 PM03:00 PM
04:00 PM04:00 PM
05:00 PM05:00 PM
06:00 PM06:00 PM
07:00 PM07:00 PM
08:00 PM08:00 PM
09:00 PM09:00 PM
10:00 PM10:00 PM
11:00 PM11:00 PM

Daylight saving time

Neither Tokyo nor Seoul observes daylight saving time — the offset between JST and KST is fixed year-round.

Working-hours overlap

9 AM–5 PM JST (9 AM–5 PM KST) — the shared 9-to-5 window for meetings.

Frequently asked questions

What is the time difference between JST and KST?+

KST (UTC+09:00) is currently 0 hours ahead of JST (UTC+09:00). This page recalculates the offset live from the IANA time-zone database, including any daylight-saving transitions.

Does JST or KST observe daylight saving time?+

Neither Tokyo nor Seoul observes daylight saving time, so the offset stays fixed all year. Times on this page always reflect the current local rules.

What are the best meeting hours between Tokyo and Seoul?+

Standard 9–5 working hours in Tokyo and Seoul overlap from 9 AM to 5 PM JST (9 AM–5 PM KST). Schedule calls inside this window to keep both sides in normal business hours.

How do I quickly convert JST to KST?+

Use the live clocks and 24-hour reference table above. Pick any hour on the JST row to see the matching KST time. The Event Planner also lets you pick a specific date and share it with attendees.

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