What is the time difference between JST and KST?

Korea Standard Time (KST) is 0 hours the same as Japan Standard Time (JST). JST uses a UTC offset of UTC+9, while KST uses UTC+9. For example, when it's 9:00 AM in JST, it's 9:00 AM in KST. This difference remains constant year-round since neither timezone observes daylight saving time. Use the conversion table above to see the exact time for each hour of the day.

How do I convert JST to KST?

JST and KST share the same UTC offset (UTC+9), so no conversion is needed. 9:00 AM JST is 9:00 AM KST. This makes scheduling meetings and calls between these two timezones straightforward since there is no time difference to account for. The conversion table above confirms that every hour maps directly.

What time is it in KST when it's noon in JST?

When it's 12:00 PM (noon) in JST, it's also 12:00 PM in KST since both timezones share the same UTC offset of UTC+9. This means lunch hour, business meetings, and deadlines occur at the same clock time in both zones. No time conversion is needed when coordinating between JST and KST.

How many hours apart is KST from JST?

JST and KST are in the same UTC offset (UTC+9), so there is no time difference between them. Events scheduled in one timezone occur at the same clock time in the other. This makes cross-timezone coordination between JST and KST regions effortless.

Is KST ahead or behind JST?

Neither — JST and KST share the same UTC offset (UTC+9) and always show the same time. Clocks in both timezones display identical hours and minutes at any given moment. There is no need to convert between these two timezones when scheduling across them.

Does JST observe daylight saving time?

No, Japan Standard Time does not observe daylight saving time. The UTC offset of UTC+9 remains the same year-round, making time conversions from JST more predictable. Countries and regions in this timezone keep their clocks unchanged regardless of the season.

Does KST observe daylight saving time?

No, Korea Standard Time does not observe daylight saving time. The UTC offset of UTC+9 remains the same year-round, making time conversions to KST more predictable. Countries and regions in this timezone keep their clocks unchanged regardless of the season.

What is the best time to call from JST to KST?

Since JST and KST share the same UTC offset, any time that works for you will also work for the other party. Standard business hours of 9:00 AM to 5:00 PM are ideal for professional calls. The conversion table above confirms that every hour aligns between these two timezones.

JST to KST Converter

Convert Japan Standard Time to Korea Standard Time. See the hour-by-hour conversion table below.

Timezone Details

Japan Standard Time

12:42 PM

Friday, April 3, 2026

JST (UTC+09:00)

Korea Standard Time

12:42 PM

Friday, April 3, 2026

KST (UTC+09:00)

Difference: +0 hours

JST DST: No

KST DST: No

24-Hour Overview

JST — 24-hour overview

12a12a

3a3a

6a6a

9a9a

10a

11a

12p12p

3p3p

6p6p

9p9p

10p

11p

NightMorningBusinessEvening

KST — 24-hour overview

12a12a

3a3a

6a6a

9a9a

10a

11a

12p12p

3p3p

6p6p

9p9p

10p

11p

NightMorningBusinessEvening

Frequently Asked Questions

Related Conversions

KST to JST EST to JST JST to EST PST to JST JST to PST GMT to JST JST to GMT IST to JST JST to IST

Cities in These Timezones

JST Cities

Tokyo Osaka Fukuoka

KST Cities

Seoul Busan

More Tools

Compare JST & KST Plan a Meeting (JST & KST)See on Map

Learn More

How Time Zones Work Understanding DST Timezone Abbreviations

External Resources

Japan Standard Time on Wikipedia Korea Standard Time on Wikipedia IANA Time Zone Database