The short answer

12am in Atlantic Standard Time is 12pm in Seoul.

Atlantic Standard Time is 12 hours behind Seoul. It falls outside the 9-to-5 in Atlantic Standard Time but lands inside working hours in Seoul.

Atlantic Standard Time
12am
Seoul
12pm
Right now
8:42amADT · UTC-03:00 · Mon, Jun 22
8:42pmKST · UTC+09:00 · Mon, Jun 22
Read across to convert
Atlantic Standard Time
ADT · UTC-03:00
8:42am ☀
Seoul
KST · UTC+09:00
8:42pm ☾
Pinned12amAtlantic Standard Time=12pmSeoul
PINNED
12amMon
12pm
WORK
1am
1pm
WORK
2am
2pm
WORK
3am
3pm
WORK
4am
4pm
WORK
5am
5pm
6am
6pm
7am
7pm
NOW
8am
8pm
9am
WORK
9pm
10am
WORK
10pm
11am
WORK
11pm
12pm
WORK
12amTue ·+1d
1pm
WORK
1amTue ·+1d
2pm
WORK
2amTue ·+1d
3pm
WORK
3amTue ·+1d
4pm
WORK
4amTue ·+1d
5pm
5amTue ·+1d
6pm
6amTue ·+1d
7pm
7amTue ·+1d
8pm
8amTue ·+1d
9pm
9amTue ·+1d
WORK
10pm
10amTue ·+1d
WORK
11pm
11amTue ·+1d
WORK
daylightnightworking hoursoverlap
Best time to meet
No shared working hours.

Atlantic Standard Time and Seoul are too far apart for a working-day overlap. The least-unsociable option is an early-morning call on one side and an evening one on the other — or hand work off asynchronously and let the planet do the waiting.

Popular conversions

Quick reference.

9amAtlantic Standard Time=9pmSeoul
12pmAtlantic Standard Time=12amSeoul · next day
3pmAtlantic Standard Time=3amSeoul · next day
5pmAtlantic Standard Time=5amSeoul · next day
9pmAtlantic Standard Time=9amSeoul · next day
In context

What each side covers.

Atlantic Standard Time
ADT · UTC-03:00
8:42am

Canada & Caribbean

Seoul
KST · UTC+09:00
8:42pm
Cities on this clock

Frequently asked

Quick answers about converting between Atlantic Standard Time and Seoul. Can't find what you need? Email [email protected].

What is the time difference between Atlantic Standard Time and Seoul?
Atlantic Standard Time is 12 hours behind Seoul right now. We always show the live, daylight-saving-correct difference, so this figure already accounts for whichever side is observing summer time today.
When it's 12am in Atlantic Standard Time, what time is it in Seoul?
12am in Atlantic Standard Time is 12pm in Seoul. It falls outside the 9-to-5 in Atlantic Standard Time but lands inside working hours in Seoul. Use the hour-by-hour table above to read any other time across.
What's the best time for a call between Atlantic Standard Time and Seoul?
There's no comfortable 9-to-5 overlap between Atlantic Standard Time and Seoul — they sit on opposite sides of the planet's working day. Plan for an early or late call on one side, or hand work off asynchronously.
Does this account for daylight saving time?
Yes. We track every clock change in both places, so the abbreviations you see — ADT and KST — are the ones actually in effect right now, not a fixed all-year value. When either side changes its clocks, this page updates automatically.
Why is the date sometimes different on each side?
When two places are far enough apart, the same moment can fall on different calendar days. That is why some conversions are marked "previous day" or "next day" — it is the same instant in time, read off two clocks that crossed midnight at different points.