Convert KST to JST
See the live time relationship between Korea Standard Time and Japan Standard Time, compare hours, and plan meetings with no offset difference.
How KST to JST Works
KST and JST both use UTC+9, so the time difference is 0 hours year-round. A time entered in Korea Standard Time matches the same clock time in Japan Standard Time.
Hour-by-Hour Time Table
Use the visual comparison grid and hour-by-hour table to line up KST and JST times across the day. Export selected times with ICS download or send them to Google Calendar and Gmail.
Schedule Meetings Accurately
Plan calls and events between South Korea and Japan without DST confusion, since both stay on UTC+9. Time data is tracked against the IANA timezone database for accurate automatic updates.
How to Convert KST to JST
Open the KST to JST converter: Go to https://www.xconvert.com/time-converter/kst-to-jst-converter to load a visual comparison grid with KST and JST aligned for instant side-by-side viewing. This page is useful when you are scheduling a supplier call between Seoul and Tokyo, coordinating a gaming launch across Korea and Japan, or planning a same-day business meeting without manually checking clocks.
Add comparison cities if your schedule involves more teams: Click + Add City and search for cities that matter to your workflow, such as Seoul, Tokyo, or other offices involved in East Asia operations. This is especially helpful for electronics manufacturing, shipping, media licensing, and regional headquarters teams that need to confirm whether a Korea-based and Japan-based schedule stays synchronized.
Select a working time block on the grid: Click Select, then drag across the colored timeline to highlight a range in purple, such as 9:00 to 12:00 KST, which matches 9:00 to 12:00 JST exactly. You can drag the center of the selection to move the whole block or use the left and right handles to resize it, making it easy to confirm that a morning meeting, afternoon review, or evening handoff appears at the same clock time in both time zones.
Export the selected meeting window: After selecting a time range, use the export options for ICS download, Google Calendar, Gmail, Copy to clipboard, or Share link. This is practical when a Seoul product team needs to send a Tokyo partner a confirmed slot that appears identically in both locations, reducing confusion for recurring calls, launch approvals, and cross-border client updates.
Understanding the KST to JST Time Difference
KST and JST have the same time, so the time difference between them is 0 hours. KST is Korea Standard Time, UTC+9, and JST is Japan Standard Time, UTC+9, which means the clock reading stays identical when converting from one to the other.
This one-to-one match makes conversion straightforward: 9:00 KST = 9:00 JST, 12:00 KST = 12:00 JST, 15:00 KST = 15:00 JST, and 18:00 KST = 18:00 JST. If a meeting invite says 3:00 PM in Korea Standard Time, participants in Japan Standard Time join at 3:00 PM local time with no adjustment.
Daylight saving time does not change this relationship because KST does not observe DST and JST does not observe DST. As a result, the difference does not change in spring, summer, autumn, or winter, and there are no months in the year when KST and JST shift apart.
KST is used in North Korea and South Korea, while JST is used in Japan. For companies working across Seoul, Busan, Tokyo, Osaka, and other major business centers, this shared UTC+9 offset simplifies regional scheduling for manufacturing, automotive supply chains, semiconductors, finance, logistics, and entertainment partnerships.
Best Times for Calls and Meetings Between KST and JST
Because KST and JST are the same time, the best meeting windows are usually the standard business hours both teams already use locally. A 9:00 KST start is 9:00 JST, which makes morning check-ins easy for Korea-Japan coordination without forcing one side into an early or late call.
Midday collaboration is equally simple. For example, 12:00 KST = 12:00 JST, so lunch-adjacent planning sessions, procurement updates, and partner reviews can be arranged without any conversion risk or concern about one team being ahead or behind.
Afternoon working sessions also line up perfectly: 15:00 KST = 15:00 JST and 18:00 KST = 18:00 JST. This is useful for end-of-day status reviews, same-day approvals, and regional operations meetings where teams in South Korea and Japan need to exchange updates before local offices close.
In practical terms, overlapping work hours are full work hours because the clocks match exactly. If both teams operate on a typical 9 AM to 6 PM schedule, every hour in that block is shared, which is ideal for product launches, customer support coordination, shipping cutoffs, and real-time communication between Korean and Japanese offices.
Frequently Asked Questions
What is the time difference between KST and JST?
The time difference between KST and JST is 0 hours, so they are the same time. KST is UTC+9 and JST is also UTC+9, which means there is no need to add or subtract hours when converting between them.
When is 9 AM KST in JST?
9:00 KST = 9:00 JST. Since Korea Standard Time and Japan Standard Time are identical, a 9 AM meeting in Korea appears as 9 AM in Japan as well, which is convenient for morning standups and client calls.
Does the difference between KST and JST change during DST?
No, the difference does not change during daylight saving time because KST does not observe DST and JST does not observe DST. That means the relationship stays the same throughout the entire year, with no seasonal clock changes to track.
What is 12 PM KST in JST?
12:00 KST = 12:00 JST. This makes noon meetings, lunch-hour check-ins, and midday operational reviews easy to schedule between teams in Korea and Japan because both sides see the same local time.
What is 3 PM KST in JST?
15:00 KST = 15:00 JST. Afternoon meetings are especially easy to coordinate because there is no conversion step, so both parties can use the same calendar time for project reviews, sales calls, or logistics updates.
What is 6 PM KST in JST?
18:00 KST = 18:00 JST. This is useful for end-of-day handoffs, media approvals, and regional wrap-up meetings where teams in both countries need to connect before the business day ends.
What is the best meeting time between KST and JST?
The best meeting time between KST and JST is usually any standard work-hour slot because the two time zones are identical. Common choices include 9:00, 12:00, 15:00, and 18:00, and each of these appears at the same local time in both Korea and Japan.
Which countries use KST and JST?
KST is used in North Korea and South Korea, while JST is used in Japan. This shared UTC+9 alignment helps organizations operating across the Korean Peninsula and Japan schedule meetings, shipments, and regional coordination without time conversion errors.