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

UTC to KST Time Converter

KST is 9 hours ahead of UTC. UTC is the zero point, UTC±00:00, and KST is UTC+9:00.

UTC
Coordinated Universal Time
03:45:31 PM
Sunday, October 11, 2026
UTC
+9:00
hours difference
⇆ Reverse
KST
Korea Standard Time
12:45:31 AM
Monday, October 12, 2026
UTC+9:00

Best Time to Call Between UTC and KST

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 1:00 PM UTC, which is 4:00 PM to 10:00 PM KST.

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

UTC to KST: Full 24-Hour Conversion Table

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

UTCKSTWorking hours
12:00 AM 9:00 AM KST only
1:00 AM 10:00 AM KST only
2:00 AM 11:00 AM KST only
3:00 AM 12:00 PM KST only
4:00 AM 1:00 PM KST only
5:00 AM 2:00 PM KST only
6:00 AM 3:00 PM KST only
7:00 AM 4:00 PM KST only
8:00 AM 5:00 PM —
9:00 AM 6:00 PM UTC only
10:00 AM 7:00 PM UTC only
11:00 AM 8:00 PM UTC only
12:00 PM 9:00 PM UTC only
1:00 PM 10:00 PM UTC only
2:00 PM 11:00 PM UTC only
3:00 PM 12:00 AM next day UTC only
4:00 PM 1:00 AM next day UTC only
5:00 PM 2:00 AM next day —
6:00 PM 3:00 AM next day —
7:00 PM 4:00 AM next day —
8:00 PM 5:00 AM next day —
9:00 PM 6:00 AM next day —
10:00 PM 7:00 AM next day —
11:00 PM 8:00 AM next day —

What UTC and KST Actually Are

UTC — Coordinated Universal Time

The global reference standard. Aviation, computing and science run on it. Standing at UTC as written, and the region does not change its clocks, so that offset holds all year.

UTC is not a place. It is a computed standard, kept within a second of mean solar time at Greenwich by atomic clocks, and it is the reference every other zone is defined against.

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.

What This Means in Practice

The date changes mid-working-day

For 2 of the eight hours in a normal UTC working day, the equivalent KST 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.

A gap you can rely on

Neither region changes its clocks, so this difference holds every day of the year. A recurring meeting booked once stays correct — worth knowing, because most cross-border pairs cannot say that.

Frequently Asked Questions

What is the time difference between UTC and KST?

KST is 9 hours ahead of UTC.

What is 9:00 AM UTC in KST?

9:00 AM UTC is 6:00 PM KST.

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

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 1:00 PM UTC, which is 4:00 PM to 10:00 PM KST.

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

No. Neither region changes its clocks, so this gap is fixed all year round.

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