JST to KST Converter

Category: Time Zone Converters

- June 20, 2025

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Japan Standard Time (JST)

UTC+9 • Tokyo, Osaka, Yokohama, Nagoya

Conversion Settings

Configure your timezone conversion preferences

Auto Convert

Daylight Saving Aware

Show UTC Offset

Korea Standard Time (KST)

UTC+9 • Seoul, Busan, Incheon, Daegu

--:--:--

Select a time to convert

Time Difference: --

UTC Offset (JST): +09:00

UTC Offset (KST): +09:00

DST Status: No DST

JST Time: --

KST Time: --

Time Format:

Current JST: --:--:--

Current KST: --:--:--

🌏 JST and KST are both UTC+9 and never observe daylight saving time. The times are identical between Japan and Korea.

JST to KST Conversion Guide

What is JST to KST Conversion?

JST to KST conversion helps you understand time coordination between Japan Standard Time and Korea Standard Time zones. Both JST and KST are UTC+9 and never observe daylight saving time, making them identical throughout the year. This simplifies business coordination and scheduling between Japan and Korea.

Time Zone Information

Japan Standard Time (JST): Used throughout all of Japan including Tokyo, Osaka, Yokohama, and Nagoya. Always UTC+9 with no daylight saving time changes.

Korea Standard Time (KST): Used in both South and North Korea including Seoul, Busan, Incheon, and Daegu. Always UTC+9 with no daylight saving time changes.

Time Difference: There is no time difference between JST and KST - they are the same time zone.

Daylight Saving Time Impact

No Daylight Saving: Neither Japan nor Korea observes daylight saving time

Year-Round Consistency: JST and KST remain UTC+9 throughout the entire year

Simplified Scheduling: No need to account for seasonal time changes when coordinating between the two countries

Common Conversion Examples

Business Hours

JST 9:00 AM = KST 9:00 AM

JST 5:00 PM = KST 5:00 PM

Identical business hours make coordination simple

Meeting Planning

JST 2:00 PM = KST 2:00 PM

JST 10:00 AM = KST 10:00 AM

No time conversion needed for meetings

Event Scheduling

JST 12:00 PM = KST 12:00 PM

JST 8:00 PM = KST 8:00 PM

Perfect synchronization for regional events

Travel Planning

Tokyo 6:00 AM = Seoul 6:00 AM

Osaka 11:30 PM = Busan 11:30 PM

No jet lag adjustment needed between countries

Conversion Tips & Best Practices

• JST and KST are identical - no time conversion is ever needed

• Both time zones remain UTC+9 throughout the entire year

• Business coordination between Japan and Korea is seamless due to identical time zones

• No daylight saving time complications - consistent year-round scheduling

• Travel between Japan and Korea requires no time adjustment

• Both countries share the same business hours and working schedules effectively

JST to KST Converter

If you regularly coordinate across Tokyo and Seoul, this little tool can save you a lot of second-guessing. It’s designed to convert time between Japan Standard Time (JST) and Korea Standard Time (KST) with just a few clicks. And since both time zones are always UTC+9, the good news is: the math’s already done for you. But there’s more to this converter than just showing two clocks.

Why even bother converting if the times are the same?

It may seem redundant at first glance. JST and KST match hour-for-hour all year long. But anyone who works internationally knows that timezone confusion still finds its way into group chats and meeting invites. Maybe you’re not sure whether to write JST or KST. Maybe your calendar app won’t stop adjusting things when it shouldn’t. This converter gives you a fast, reliable reference—no calculations, no missteps.

How to use it step by step

1. Set the time

Start with the date and time you want to convert. Use the calendar and time input fields in the Japan or Korea section (whichever one is currently the “input” zone). Don’t worry if you enter JST but really meant KST—you can easily swap the zones with a single button press.

2. Choose the input time zone

Right below the time entry, there’s a dropdown menu that lets you select whether your input is in JST or KST. By default, it starts on Japan. Once selected, the tool will treat that time as being in that zone and show you the equivalent in the other.

3. Convert

Tap the Convert Time button—or just press spacebar or Enter. You’ll instantly see the equivalent time in the opposite zone, along with date, UTC offset, and other details.

4. Bonus buttons to speed things up

Swap: Switches input and output zones instantly. Handy if you got them flipped.
Now: Drops in the current local time based on your selected zone.
Reset: Restores everything to default, including today’s date and current hour.

What’s happening under the hood

This tool isn’t just displaying static times. It calculates the precise UTC-based time internally and formats both zones using your chosen settings. Even if you switch to 12-hour mode, turn on UTC offsets, or want seconds shown, the results stay consistent and clear.

Live clocks built in

At the bottom of the converter, you’ll see two real-time clocks showing the current time in JST and KST. They update every second and use your selected format (12 or 24 hour). No guessing what time it is right now in either country.

Optional display settings

Auto Convert: When enabled, any time or date you enter triggers an instant conversion—no button press needed.
Show UTC Offset: Adds more detail about the +9:00 difference from UTC if you like having that info visible.
DST Awareness: This one’s disabled because there’s nothing to worry about. Neither Japan nor Korea uses daylight saving time, ever.

Switching between 12-hour and 24-hour

A small toggle near the bottom lets you switch how the time is displayed. Want AM/PM? Stick with 12-hour. Prefer military-style? Click to flip it to 24-hour mode.

Answering what users often ask

“Isn’t JST and KST the same?”

Yes. This converter confirms that for you, while making it easier to share and communicate clearly with others across borders.

“Why does it still have a swap button?”

Because context matters. Even though the times are identical, sometimes you're entering a meeting time in Seoul and want to frame it for colleagues in Tokyo - or vice versa.

“What if I try to enter a time but leave the date blank?”

The tool won’t break, but you won’t get a result either. It needs both date and time to work properly. If it can't convert, it resets the display.

“Why does it say ‘No DST’ all over?”

To reassure you. Some time converters factor in daylight saving, which can shift time by an hour. Here, it’s locked. Both countries run UTC+9 year-round.

Stay on track with Japan–Korea timing

This converter helps take the uncertainty out of time coordination between two close but distinct countries. Whether you're setting up a call, confirming an arrival time, or just double-checking your schedule, it gives you fast clarity—without relying on memory or manual math. And because it’s built with live updates, smart shortcuts, and real timezone data, it works reliably no matter when you use it.

JST to KST Converter

Japan Standard Time (JST)

Conversion Settings

Korea Standard Time (KST)

JST to KST Conversion Guide

What is JST to KST Conversion?

Time Zone Information

Daylight Saving Time Impact

Common Conversion Examples

Conversion Tips & Best Practices

JST to KST Converter

Why even bother converting if the times are the same?

How to use it step by step

1. Set the time

2. Choose the input time zone

3. Convert

4. Bonus buttons to speed things up

What’s happening under the hood

Live clocks built in

Optional display settings

Switching between 12-hour and 24-hour

Answering what users often ask

“Isn’t JST and KST the same?”

“Why does it still have a swap button?”

“What if I try to enter a time but leave the date blank?”

“Why does it say ‘No DST’ all over?”

Stay on track with Japan–Korea timing

Time Zone Converters Calculators:

Time now in these cities:

Time now in countries:

Time now in time zones: