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—
San Juan · Barbados · Halifax (winter)
Find the best shared slot in the date and time meeting planner.
Difference
KST vs AST
UTC → UTC
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Seoul · Busan
AST to KST converter
AST to KST Converter
Convert AST (San Juan) to KST (Seoul) now. Live clocks, the current time difference, and a simple meeting window — free.
America/Puerto_Rico
—
AST → KST
To · Korea Standard Time
—
Asia/Seoul
Interactive diagram
Watch AST convert into KST
Drag the Atlantic hour. Watch the Korea clock change.
Atlantic
9:00 AM AST
—
KST ← AST
Korea
—
Full-day chart
AST to KST hourly conversion chart
Full-day table. Tap a row to copy. Labels follow daylight saving.
| Atlantic | Korea | UTC offsets |
|---|
Meeting times
Best AST to KST meeting window
Find hours that work on both sides. Then save the slot to your calendar.
Follow along
Step-by-step AST to KST conversion
Four short steps to convert any AST time to KST.
Choose AST time
Select any hour in Atlantic Standard Time. Smart mode uses America/Puerto_Rico.
AST to KST conversion guide
AST to KST conversion guide
This AST to KST converter shows Korea Standard Time (UTC+9) for any Atlantic Standard Time (UTC−4) time. Use it to schedule between San Juan and Seoul. Choose Smart DST for live city clocks. Choose Fixed mode when you only want the AST and KST labels.
Atlantic
AST
UTC−4
San Juan · Barbados · Halifax (winter)
AST vs KST—
Korea
KST
UTC+9
Seoul · Busan
What is AST to KST conversion?
AST to KST conversion turns a AST clock into the matching KST time. Use it for calls, travel, and teams in San Juan and Seoul.
AST to KST time difference
KST is 13 hours ahead of AST. Add 13 hours to the AST time to get KST. The live clocks at the top show the current AST to KST gap.
AST vs KST
AST is UTC−4. KST is UTC+9. They are different names. If a region uses daylight saving, check the live labels.
AST to KST now / current time
Need ast to kst right now? Read the live clocks, or tap Use current time for an instant AST → KST result.
AST to KST time difference
Season / context — tap to explore
See how daylight saving can change this pair.
Atlantic—
—AST → KST
Korea—
Quick answers
Atlantic
Atlantic Standard Time (AST)
UTC−4
Atlantic Standard Time (AST) is UTC−4. Smart DST uses the city clock America/Puerto_Rico so daylight saving stays correct for San Juan · Barbados · Halifax (winter).
- Cities: San Juan · Barbados · Halifax (winter)
- City clock: America/Puerto_Rico
- Fixed AST: UTC−4
- On this page it pairs with KST (UTC+9)
Korea
Korea Standard Time (KST)
UTC+9
Korea Standard Time (KST) is UTC+9. Smart DST uses Asia/Seoul for cities such as Seoul · Busan.
- Cities: Seoul · Busan
- City clock: Asia/Seoul
- Fixed KST: UTC+9
- From AST: KST is 13 hours ahead of AST
AST to KST FAQ
Common AST to KST questions
What is the AST to KST time difference?
KST is 13 hours ahead of AST. Fixed labels: AST = UTC−4, KST = UTC+9. Add 13 hours to the AST time to get KST.
How do I convert AST to KST quickly?
Add 13 hours to the AST time to get KST. Example: 3:00 AM AST → 4:00 PM KST. Or use the live AST to KST converter above.
Is KST the same as AST?
No. AST is UTC−4 (San Juan · Barbados · Halifax (winter)). KST is UTC+9 (Seoul · Busan).
What is a good AST to KST meeting time?
KST is ahead. Try 7:00–11:00 AM AST. That is about 8:00 PM–12:00 AM KST. Use the meeting planner on this page to export an ICS or Google Calendar invite.
What cities use AST and KST?
AST is common in San Juan · Barbados · Halifax (winter). KST is common in Seoul · Busan. Smart DST uses America/Puerto_Rico and Asia/Seoul.