Question 1

What is the time difference between KST and JST right now?

Accepted Answer

Korea Standard Time (KST) is UTC+9 and Japan Standard Time (JST) is UTC+9. The exact time difference between KST and JST can change when one or both zones transition into or out of daylight saving time.

Question 2

Does KST or JST observe daylight saving time?

Accepted Answer

Daylight saving time observance varies by region. Korea Standard Time and Japan Standard Time may or may not observe DST. The converter on this page automatically adjusts for any DST changes in either KST or JST.

Question 3

When is the best time to schedule a meeting between KST and JST?

Accepted Answer

The best meeting window between KST and JST is shown on this page in the working-hours overlap section. It is computed from real 9am-5pm working windows in Seoul and Tokyo for today.

Question 4

What time is it in Tokyo when it is 12:00 noon in Seoul?

Accepted Answer

When it is 12:00 PM (noon) in Seoul (KST), the equivalent time in Tokyo (JST) is shown in the hour-by-hour conversion table on this page. The converter accounts for daylight saving time wherever it applies.

Question 5

Which IANA time zone identifiers are used for KST and JST?

Accepted Answer

KST maps to the IANA identifier "Asia/Seoul". JST maps to "Asia/Tokyo". These canonical identifiers are what most software libraries use to convert times accurately, including daylight saving handling.

Question 6

Is Seoul ahead of or behind Tokyo?

Accepted Answer

Whether Seoul (KST) is ahead of or behind Tokyo (JST) depends on the current UTC offsets shown on this page. The live converter and side-by-side clocks above will always reflect the current direction.

Question 7

What are the current UTC offsets for KST and JST?

Accepted Answer

KST is UTC+9 and JST is UTC+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.

Question 8

Can I schedule meetings during business hours for both KST and JST?

Accepted Answer

The "When can KST and JST meet?" section on this page tells you whether the standard 9am-5pm working hours in Seoul and Tokyo overlap, and if so, the exact window you can schedule a meeting without inconveniencing either side.

KST time (Seoul)	JST time (Tokyo)	Status
00:00 Mon	00:00 Mon	Off-hours both sides
01:00 Mon	01:00 Mon	Off-hours both sides
02:00 Mon	02:00 Mon	Off-hours both sides
03:00 Mon	03:00 Mon	Off-hours both sides
04:00 Mon	04:00 Mon	Off-hours both sides
05:00 Mon	05:00 Mon	Off-hours both sides
06:00 Mon	06:00 Mon	Off-hours both sides
07:00 Mon	07:00 Mon	Off-hours both sides
08:00 Mon	08:00 Mon	Off-hours both sides
09:00 Mon	09:00 Mon	Both at work
10:00 Mon	10:00 Mon	Both at work
11:00 Mon	11:00 Mon	Both at work
12:00 Mon	12:00 Mon	Both at work
13:00 Mon	13:00 Mon	Both at work
14:00 Mon	14:00 Mon	Both at work
15:00 Mon	15:00 Mon	Both at work
16:00 Mon	16:00 Mon	Both at work
17:00 Mon	17:00 Mon	Off-hours both sides
18:00 Mon	18:00 Mon	Off-hours both sides
19:00 Mon	19:00 Mon	Off-hours both sides
20:00 Mon	20:00 Mon	Off-hours both sides
21:00 Mon	21:00 Mon	Off-hours both sides
22:00 Mon	22:00 Mon	Off-hours both sides
23:00 Mon	23:00 Mon	Off-hours both sides

KST to JST Time Converter

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Daylight Saving status right now

When can KST and JST meet?

Hour-by-hour KST to JST conversion table

About these time zones

Sun today in Seoul and Tokyo

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