World Timezones

KST to AST-ATLANTIC Converter

Compare AST-ATLANTIC to KST instead
Korea Standard Time1:36 pmFri, Jun 5
Korea Standard TimeKST
Asia · UTC+9
1:36 pmFri, Jun 5
12a
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Atlantic TimeADT
North America · UTC-3
1:36 amFri, Jun 5
12p
1p
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Offset

The time difference between Korea Standard Time and Atlantic Time is 12 hours.

12 hours

Korea Standard Time (KST) is ahead of Atlantic Time (ADT).

KST: UTC+9

ADT: UTC-3

Atlantic Time is currently observing daylight saving time; Korea Standard Time is not.

When to schedule

Standard business hours (9 AM–5 PM, Mon–Fri) in Korea Standard Time and Atlantic Time don't overlap on the same weekday. Atlantic Time is 12 hours behind Korea Standard Time.

With some flexibility, there’s a workable window outside standard hours:

  • 7 PM–8 PM in Korea Standard Time (7 AM–8 AM in Atlantic Time) — suggest 7:00 PM Korea Standard Time (7:00 AM Atlantic Time).

This means an early start or late finish for one side, but it’s a reasonable slot for a one-off meeting.

This window may shift by an hour during daylight saving time.

Public holidays in 2026

National public holidays can affect availability — a counterpart is likely off work on their own holidays, so it's worth planning meetings and deadlines around them.

South Korea

  • New Year's DayThu, Jan 1
  • Lunar New YearMon, Feb 16
  • Lunar New YearTue, Feb 17
  • Lunar New YearWed, Feb 18
  • Independence Movement DayMon, Mar 2
  • Labour DayFri, May 1
  • Children's DayTue, May 5
  • Buddha's BirthdayMon, May 25
  • Local Election DayWed, Jun 3
  • Memorial DaySat, Jun 6
  • Constitution DayFri, Jul 17
  • Liberation DayMon, Aug 17
  • ChuseokThu, Sep 24
  • ChuseokFri, Sep 25
  • ChuseokSat, Sep 26
  • National Foundation DayMon, Oct 5
  • Hangul DayFri, Oct 9
  • Christmas DayFri, Dec 25

Canada

  • New Year's DayThu, Jan 1
  • Good FridayFri, Apr 3
  • Victoria DayMon, May 18
  • Canada DayWed, Jul 1
  • Labour DayMon, Sep 7
  • National Day for Truth and ReconciliationWed, Sep 30
  • ThanksgivingMon, Oct 12
  • Christmas DayFri, Dec 25

About these zones

Korea Standard Time is also known as KST. To call South Korea, dial +82.

Atlantic Time is also known as AST, or ADT. To call Canada, dial +1.

Atlantic Time is approximately 6,700 miles north of Korea Standard Time.

Quick reference

Full 24-hour conversion table — tap any time to open it in the converter.

KSTAST-ATLANTICDay
12:00 am12:00 pm-1 day
1:00 am1:00 pm-1 day
2:00 am2:00 pm-1 day
3:00 am3:00 pm-1 day
4:00 am4:00 pm-1 day
5:00 am5:00 pm-1 day
6:00 am6:00 pm-1 day
7:00 am7:00 pm-1 day
8:00 am8:00 pm-1 day
9:00 am9:00 pm-1 day
10:00 am10:00 pm-1 day
11:00 am11:00 pm-1 day
12:00 pm12:00 amSame day
1:00 pm1:00 amSame day
2:00 pm2:00 amSame day
3:00 pm3:00 amSame day
4:00 pm4:00 amSame day
5:00 pm5:00 amSame day
6:00 pm6:00 amSame day
7:00 pm7:00 amSame day
8:00 pm8:00 amSame day
9:00 pm9:00 amSame day
10:00 pm10:00 amSame day
11:00 pm11:00 amSame day

Daylight saving time

Atlantic Time observes daylight saving time; Korea Standard Time does not. The offset between the two zones changes when Atlantic Time transitions: on Sunday, November 1, 2026, clocks fall back from ADT to AST.

See the daylight saving time page for transition dates across every time zone.

Daylight today

Korea Standard Time
Sunrise
5:12 AM
Sunset
7:51 PM
Day length
14h 38m
Atlantic Time
Sunrise
5:31 AM
Sunset
8:56 PM
Day length
15h 25m

Daylight overlap: 2h 19m — 5:31 PM–7:51 PM in Korea Standard Time (5:31 AM–7:51 AM in Atlantic Time). Both locations are in daylight during this window.

Cities in these zones

Cities in Atlantic Time

Browse all cities to see the current local time anywhere.

Airports in these zones

Airports in Korea Standard Time

  • GMP
  • ICN
  • PUS
  • TAE
  • CJJ
  • KWJ
  • MWX

Airports in Atlantic Time

  • YHZ

Related conversions

Common conversions

What is 9:00 am KST in AST-ATLANTIC?
9:00 am KST is 9:00 pm AST-ATLANTIC, the previous day.
What is 12:00 pm KST in AST-ATLANTIC?
12:00 pm KST is 12:00 am AST-ATLANTIC.
What is 12:30 pm KST in AST-ATLANTIC?
12:30 pm KST is 12:30 am AST-ATLANTIC.
What is 2:00 pm KST in AST-ATLANTIC?
2:00 pm KST is 2:00 am AST-ATLANTIC.
What is 5:00 pm KST in AST-ATLANTIC?
5:00 pm KST is 5:00 am AST-ATLANTIC.
What is 11:30 pm KST in AST-ATLANTIC?
11:30 pm KST is 11:30 am AST-ATLANTIC.