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).
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.
Common Times Converted
KST on the left, EST on the right.
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.
| KST | EST | Working 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.
Major Cities in Each Zone
Cities on KST
Cities on EST
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.