JST to KST Time Converter
Use this JST to KST time converter to compare Japan and South Korea time instantly. KST is 0 hours equal to JST, so 9:00 AM JST becomes 9:00 AM KST and 5:00 PM JST becomes 5:00 PM KST. The page is useful for business-hours overlap, international calls, remote-team handoffs, webinars, and travel planning, with daylight saving adjustments handled automatically.
JST to KST Quick Facts
Use this JST to KST converter to compare Japan and South Korea time, check the 0 hours gap, and confirm the right slot for calls, handoffs, and deadlines. Good overlap starts around 9:00 AM JST / 9:00 AM KST.
How to Convert JST to KST
Converting between Japan Standard Time and Korea Standard Time means no offset adjustment — here's how to do it in under 10 seconds with no sign-up.
Pick the date and time in Japan Standard Time (UTC +9) that you want to convert. Hit "Now" to load the current JST time instantly, or use "+1h" to step forward and compare.
The equivalent Korea Standard Time (UTC +9) time appears immediately. Since KST is 0 hours behind of JST, most daytime conversions stay on the same calendar day.
Click "Copy Time" to grab the KST result for your calendar or message. Use "+1d" to check how the conversion shifts across dates — useful when Daylight Saving Time changes the gap.
Why Choose Our JST to KST Converter
When someone in Japan suggests 9:00 AM JST, that's 9:00 AM KST. This converter shows the overlap so both sides agree on one slot — no back-and-forth.
Late-night JST times can land on a different date in KST because of the 0 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.
Daylight Saving adjustments can widen or narrow the JST–KST 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.
Product launches, sports matches, and webinars are often announced in JST. Convert the event time to KST so you know exactly when to tune in — since both zones share the same offset, no conversion is needed but this tool confirms it instantly.
JST to KST Time Conversion Chart
Quick-reference conversion table covering every hour of the day at a glance.
Japan Standard Time to Korea Standard Time full day schedule
| Japan Standard Time | Korea Standard Time |
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| 12:00 AM |
12:00 AM
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| 1:00 AM |
1:00 AM
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| 2:00 AM |
2:00 AM
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| 3:00 AM |
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| 4:00 AM |
4:00 AM
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| 5:00 AM |
5:00 AM
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| 6:00 AM |
6:00 AM
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| 7:00 AM |
7:00 AM
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| 8:00 AM |
8:00 AM
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| 9:00 AM |
9:00 AM
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| 10:00 AM |
10:00 AM
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| 11:00 AM |
11:00 AM
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| 12:00 PM |
12:00 PM
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| 1:00 PM |
1:00 PM
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| 2:00 PM |
2:00 PM
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| 3:00 PM |
3:00 PM
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| 4:00 PM |
4:00 PM
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| 5:00 PM |
5:00 PM
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| 6:00 PM |
6:00 PM
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| 7:00 PM |
7:00 PM
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| 8:00 PM |
8:00 PM
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| 9:00 PM |
9:00 PM
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| 10:00 PM |
10:00 PM
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| 11:00 PM |
11:00 PM
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Timezone offsets and DST rules verified against the IANA Time Zone Database. Conversion math and business-hour overlap windows double-checked against real-world scheduling scenarios.
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JST to KST FAQ
Quick answers about daylight saving time, date changes, business-hour overlap, and the most common scheduling questions between Japan Standard Time and Korea Standard Time.
What is the time difference between JST and KST?
When can JST and KST have business-hour overlap?
Does JST or KST observe daylight saving time?
How do I quickly convert JST to KST?
Popular JST Time Converters
Explore more JST 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 KST
Find the time difference from any major zone into Korea Standard Time. Use these pages when scheduling with South Korea from a different region.