Convert JST to KST
See the current time difference, compare hours side by side, and plan meetings between Japan Standard Time and Korea Standard Time.
How to Convert JST to KST
Open the JST to KST converter: Go to https://www.xconvert.com/time-converter/jst-to-kst-converter. The page loads with Japan Standard Time and Korea Standard Time already set up, which is useful if you are scheduling a supplier call between Tokyo and Seoul, confirming a flight connection between Haneda and Incheon, or coordinating a product launch across Japanese and South Korean teams.
Add comparison cities if your schedule involves more than Japan and South Korea: Click “+ Add City” and search for cities such as Tokyo, Seoul, and a third hub like Singapore or Los Angeles if your team also includes APAC operations or US headquarters. This is especially practical for electronics, automotive, gaming, and shipping companies that often coordinate between Japan, South Korea, and regional offices in other markets.
Drag on the grid to select a meeting window: Click “Select” if needed, then drag across the colored timeline on the JST row to highlight a time range in purple; you can resize it with the left and right handles or move the whole block by dragging the center. For example, if you drag from 9:00 AM to 11:00 AM JST, the KST row will show 9:00 AM to 11:00 AM KST as well, confirming that a morning engineering sync between Tokyo and Seoul happens at the same local clock time in both countries.
Export and share the selected time: Once the purple range is selected, use the export options for ICS download, Google Calendar, Gmail, Copy to clipboard, or Share link. This is helpful when sending a confirmed meeting slot to a Japan-Korea procurement team, inviting remote game developers in both countries, or creating a calendar event that automatically appears in each participant’s local time without manual conversion.
Understanding the JST to KST Time Difference
Japan Standard Time (JST) is UTC+9, and Korea Standard Time (KST) is also UTC+9. That means the exact time difference between JST and KST is 0 hours year-round, so 9:00 AM JST is always 9:00 AM KST, 3:30 PM JST is always 3:30 PM KST, and there is no need to add or subtract hours when converting between Tokyo and Seoul.
Daylight saving time does not currently affect this conversion because Japan does not observe DST and South Korea does not currently observe DST either. As a result, the JST-KST difference does not change in March, June, October, or November, unlike conversions involving New York, London, or Sydney where DST shifts can change the offset seasonally.
This fixed alignment is useful for industries with frequent Japan-Korea coordination, including semiconductor manufacturing, automotive supply chains, entertainment licensing, container shipping, and regional airline operations. Since both countries stay on the same UTC offset throughout the year, recurring meetings, market monitoring, and logistics handoffs can usually be scheduled at the same clock time every month without seasonal adjustment.
Best Times for Calls and Meetings Between JST and KST
Because JST and KST are identical at UTC+9, the overlapping work window is effectively the full business day in both countries. A standard office overlap of 9:00 AM to 6:00 PM JST = 9:00 AM to 6:00 PM KST works well for internal meetings, client calls, procurement reviews, and cross-border project check-ins between Tokyo, Osaka, Seoul, and Busan.
For focused collaboration, 9:00 AM to 11:00 AM JST = 9:00 AM to 11:00 AM KST is often one of the best slots for engineering standups, trading desk coordination, and manufacturing status calls because both teams are online early and have not yet moved into afternoon deadlines. Another strong option is 2:00 PM to 4:00 PM JST = 2:00 PM to 4:00 PM KST, which suits sales reviews, partner presentations, and media or gaming meetings after lunch.
If you need to work around travel or operations schedules, evening calls remain easy to interpret because the clocks still match exactly: 7:00 PM JST = 7:00 PM KST and 10:00 PM JST = 10:00 PM KST. That simplicity is useful for same-day flight planning on major routes such as Tokyo-Seoul, for customer support teams covering both markets, and for regional leadership calls where avoiding conversion errors matters more than anything else.
Frequently Asked Questions
What is the time difference between JST and KST?
The time difference between JST and KST is 0 hours. Both Japan Standard Time and Korea Standard Time use UTC+9, so the local clock time is the same in Japan and South Korea throughout the year.
When is 9 AM JST in KST?
9:00 AM JST is 9:00 AM KST. Since there is no offset between the two time zones, every hour converts directly, which makes scheduling meetings between Tokyo and Seoul much easier than scheduling with regions that observe daylight saving time.
Does the difference between JST and KST change during DST?
No, the difference does not change during daylight saving time periods because neither Japan nor South Korea currently observes DST. That means the JST to KST conversion remains 0 hours in January, April, July, October, and every other month.
What is the best meeting time between JST and KST?
The best meeting time is usually any shared business-hour block such as 9:00 AM-11:00 AM or 2:00 PM-4:00 PM in both time zones. Because JST and KST are identical, companies can set recurring meetings at the same local time for teams in Tokyo and Seoul without needing seasonal calendar updates.
Is Tokyo the same time as Seoul?
Yes, Tokyo and Seoul are on the same current standard time, with both cities operating at UTC+9. This is especially convenient for airlines, exporters, gaming companies, and multinational teams that need to coordinate same-day work across Japan and South Korea.
How do I convert JST to KST on https://www.xconvert.com?
Open the JST to KST page, use the visual comparison grid, and drag across the JST timeline to highlight the time you want to check. The KST row will display the exact same clock range, and you can then export the result as an ICS file, send it through Google Calendar or Gmail, copy it to the clipboard, or share a direct link with colleagues.
Are Japan and South Korea always the same time?
Under current timekeeping rules, yes, Japan and South Korea are always the same time because both use UTC+9 and neither country currently switches clocks seasonally. Unless one of the countries changes national time policy in the future, the conversion between JST and KST remains constant all year.