JST to KST Time Converter

Convert Japan Standard Time (JST) to Korea Standard Time (KST). Both time zones are shown live below; current offset between them is same time.

Tokyo · Japan Standard Time
11:48:25
Tuesday, May 12, 2026
GMT+9 · UTC+09:00
Seoul · Korea Standard Time
11:48:25
Tuesday, May 12, 2026
GMT+9 · UTC+09:00

Convert a specific time

From: JST (Tokyo)
To: KST (Seoul)
--:--

Daylight Saving status right now

JST (Japan Standard Time)
Observes DST
No
KST (Korea Standard Time)
Observes DST
No

When can JST and KST meet?

00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
JST
KST
Both zones in working hours (9am-5pm)
One zone working
Off-hours
Columns are hours of the day in Tokyo (JST). Each row shows the local working-hours state in that zone for the same moment in time.
8 hours of overlap during standard 9am-5pm working hours.
Best meeting window: 09:00–16:00 JST (09:00–16:00 KST).

Hour-by-hour JST to KST conversion table

JST time (Tokyo)KST time (Seoul)Status
00:00 Tue00:00 TueOff-hours both sides
01:00 Tue01:00 TueOff-hours both sides
02:00 Tue02:00 TueOff-hours both sides
03:00 Tue03:00 TueOff-hours both sides
04:00 Tue04:00 TueOff-hours both sides
05:00 Tue05:00 TueOff-hours both sides
06:00 Tue06:00 TueOff-hours both sides
07:00 Tue07:00 TueOff-hours both sides
08:00 Tue08:00 TueOff-hours both sides
09:00 Tue09:00 TueBoth at work
10:00 Tue10:00 TueBoth at work
11:00 Tue11:00 TueBoth at work
12:00 Tue12:00 TueBoth at work
13:00 Tue13:00 TueBoth at work
14:00 Tue14:00 TueBoth at work
15:00 Tue15:00 TueBoth at work
16:00 Tue16:00 TueBoth at work
17:00 Tue17:00 TueOff-hours both sides
18:00 Tue18:00 TueOff-hours both sides
19:00 Tue19:00 TueOff-hours both sides
20:00 Tue20:00 TueOff-hours both sides
21:00 Tue21:00 TueOff-hours both sides
22:00 Tue22:00 TueOff-hours both sides
23:00 Tue23:00 TueOff-hours both sides

Times computed for today in each zone using the IANA time zone database. The conversion accounts for daylight saving time wherever applicable.

About these time zones

Japan Standard Time (JST)
IANA identifier
Asia/Tokyo
Current UTC offset
UTC+09:00
Current abbreviation
GMT+9
Major cities in this zone
TokyoOsakaKyotoYokohama
Korea Standard Time (KST)
IANA identifier
Asia/Seoul
Current UTC offset
UTC+09:00
Current abbreviation
GMT+9
Major cities in this zone
SeoulBusan

Sun today in Tokyo and Seoul

Tokyo
Sunrise
04:40
Sunset
18:37
Solar noon
11:39
Daylight
13h 56m
Seoul
Sunrise
05:27
Sunset
19:32
Solar noon
12:29
Daylight
14h 4m

Related converters

KST to JST (reverse)JST to ESTJST to PSTJST to GMTJST to UTCJST to CETEST to KSTPST to KSTGMT to KSTUTC to KSTCET to KST
Looking for local time? See time in Tokyo or time in Seoul.

Frequently asked questions

What is the time difference between JST and KST right now?+
KST (Korea Standard Time) is currently same time JST (Japan Standard Time). The exact difference can change when one or both zones transition into or out of daylight saving time.
Does JST or KST observe daylight saving time?+
JST: does not observe daylight saving time. KST: does not observe daylight saving time.
When is the best time to schedule a meeting between JST and KST?+
The strongest overlap is 09:00–16:00 JST (09:00–16:00 KST), giving 8 hours when both sides are within standard 9am-5pm working hours.
What time is it in Seoul when it is 12:00 noon in Tokyo?+
When it is 12:00 Tue in Tokyo (JST), it is 12:00 Tue in Seoul (KST).
Which IANA time zone identifiers are used for JST and KST?+
JST maps to "Asia/Tokyo" in the IANA database. KST maps to "Asia/Seoul". These identifiers are what most software libraries use to convert times accurately, including DST handling.
Is Tokyo ahead of or behind Seoul?+
Whether Tokyo (JST) is ahead of or behind Seoul (KST) depends on the current UTC offsets. Right now KST is same time JST. The live converter and side-by-side clocks above always reflect the current direction.
What are the current UTC offsets for JST and KST?+
JST is UTC+09:00 (GMT+9) and KST is UTC+09:00 (GMT+9). Both offsets shift by one hour when the corresponding region enters or exits daylight saving time, so the live values on this page are the source of truth.
Can I schedule meetings during business hours for both JST and KST?+
Yes. There are 8 hours of overlap during standard 9am-5pm working hours, with the strongest window at 09:00–16:00 JST.