Convert any time between KST and EST, with a full 24-hour table and the hours when both sides are actually at work.

KST to EST Time Converter

EST is 13 hours behind KST. KST is UTC+9:00, and The US East Coast is currently on EDT (UTC-4:00).

Worth knowing right now. The US East Coast is currently on EDT, not EST, because daylight saving is in effect. The 13 hours above is the gap between those two regions today, which is almost certainly what you want. Taken strictly as written, KST to EST is 14 hours.
KST
Korea Standard Time
12:07:06 AM
Monday, October 12, 2026
UTC+9:00
-13:00
hours difference
⇆ Reverse
EST
Eastern Standard Time
11:07:06 AM
Sunday, October 11, 2026
UTC-4:00

Best Time to Call Between KST and EST

Standard 9-to-5 hours in these two zones never overlap, so someone has to take the call outside their working day. The most workable window is 7:00 AM to 11:00 AM KST, which is 6:00 PM to 10:00 PM EST.

both at work KST only EST only neither  —  hours along the strip are KST.

KST to EST: Full 24-Hour Conversion Table

Shaded rows are working hours; the darker shade marks the hours when both zones are at work.

KSTESTWorking hours
12:00 AM 11:00 AM prev day EST only
1:00 AM 12:00 PM prev day EST only
2:00 AM 1:00 PM prev day EST only
3:00 AM 2:00 PM prev day EST only
4:00 AM 3:00 PM prev day EST only
5:00 AM 4:00 PM prev day EST only
6:00 AM 5:00 PM prev day —
7:00 AM 6:00 PM prev day —
8:00 AM 7:00 PM prev day —
9:00 AM 8:00 PM prev day KST only
10:00 AM 9:00 PM prev day KST only
11:00 AM 10:00 PM prev day KST only
12:00 PM 11:00 PM prev day KST only
1:00 PM 12:00 AM KST only
2:00 PM 1:00 AM KST only
3:00 PM 2:00 AM KST only
4:00 PM 3:00 AM KST only
5:00 PM 4:00 AM —
6:00 PM 5:00 AM —
7:00 PM 6:00 AM —
8:00 PM 7:00 AM —
9:00 PM 8:00 AM —
10:00 PM 9:00 AM EST only
11:00 PM 10:00 AM EST only

What KST and EST Actually Are

KST — Korea Standard Time

Seoul, Busan, Incheon. Standing at UTC+9:00 as written, and the region does not change its clocks, so that offset holds all year.

South Korea has used daylight saving only twice, most recently for the 1988 Seoul Olympics, and has kept a fixed offset since.

EST — Eastern Standard Time

New York, Toronto, Washington DC, Atlanta, Miami, Boston. Standing at UTC-5:00 as written, and the region does change its clocks, so its live offset moves by an hour twice a year. The next change is on Sunday, November 1, 2026, to EST. Australia also uses EST for its own Eastern Standard Time (UTC+10), now more often written AEST.

Eastern Standard Time is only actually in force from early November to mid-March. For the other eight months the same region is on EDT, which is why so many EST conversions are quietly wrong.

What This Means in Practice

The date changes mid-working-day

For 4 of the eight hours in a normal KST working day, the equivalent EST time falls on a different calendar date. Anything scheduled in that stretch needs the date checked as well as the time, or a Tuesday call quietly becomes a Wednesday one at the other end.

This gap is not fixed

EST changes its clocks and KST does not, so the difference between them moves by an hour twice a year. A recurring meeting set now will drift for one side from Sunday, November 1, 2026 unless someone resets it.

Nearly opposite sides of the clock

At 13 hours apart, one side's morning is the other side's night. Handing work over at the end of a shift usually beats trying to get both parties in the same call.

Frequently Asked Questions

What is the time difference between KST and EST?

EST is 13 hours behind KST. That is the live figure. Taken strictly as written, the gap between KST and EST is 14 hours — the two differ because at least one of these regions is currently on daylight saving.

What is 9:00 AM KST in EST?

9:00 AM KST is 8:00 PM the previous day EST.

What are the best hours to schedule a call between KST and EST?

Standard business hours in these two zones do not overlap at all, so one side has to work outside the 9-to-5. The most workable window is 7:00 AM to 11:00 AM KST, which is 6:00 PM to 10:00 PM EST.

Does the difference between KST and EST change during the year?

Yes. EST observes daylight saving and KST does not, so the gap shifts by an hour at least twice a year. The next clock change is on Sunday, November 1, 2026.

Does EST always mean Eastern Standard Time?

Australia also uses EST for its own Eastern Standard Time (UTC+10), now more often written AEST.

Converting between two time zones regularly? Bookmark this page — the clocks update live and the table follows daylight saving automatically.