Seoul is 9 hours ahead UTC in winter and 9 hours ahead UTC in summer — 9 hours ahead of UTC in winter. Its standard offset is UTC+09:00, and it does not observe daylight saving, so the difference never changes. This page explains the difference, shows it month by month, and gives the conversion tables in both directions.
Try the tool: UTC Converter — convert any time between UTC and Seoul, with the offset for the date you pick.
How far is Seoul from UTC?
The difference between Seoul and UTC is the offset: UTC+09:00 in standard time. When it is noon in Seoul, it is still morning in London — the day in Seoul is 9 hours ahead the day at Greenwich. The sign matters: a positive offset means ahead of UTC (east of Greenwich), a negative offset means behind it (west of Greenwich).
In practical terms, the difference means that the working day in Seoul (09:00–17:00 local) is 00:00–08:00 UTC in January and 00:00–08:00 UTC in July. A team that schedules in UTC needs to know both numbers, because a meeting set for 15:00 UTC is 00:00 in Seoul in January and 00:00 in July — and one of those may be outside the working day even when the other is inside it.
Seoul vs UTC through the year
The offset on the 15th of each month in 2026. If the table shows one value all year, Seoul does not observe daylight saving. If it shows two values, the change between them is the clock change.
| Month | Offset from UTC |
|---|---|
| January | UTC+09:00 |
| February | UTC+09:00 |
| March | UTC+09:00 |
| April | UTC+09:00 |
| May | UTC+09:00 |
| June | UTC+09:00 |
| July | UTC+09:00 |
| August | UTC+09:00 |
| September | UTC+09:00 |
| October | UTC+09:00 |
| November | UTC+09:00 |
| December | UTC+09:00 |
The clock changes are: in 2026, none; in 2027, none. For the full story, see the Seoul DST 2026 page and the daylight saving checker.
Conversion tables
UTC to Seoul, for eight hours of the day:
| UTC | Seoul (January) | Seoul (July) |
|---|---|---|
| 00:00 | 09:00 | 09:00 |
| 03:00 | 12:00 | 12:00 |
| 06:00 | 15:00 | 15:00 |
| 09:00 | 18:00 | 18:00 |
| 12:00 | 21:00 | 21:00 |
| 15:00 | 00:00 | 00:00 |
| 18:00 | 03:00 | 03:00 |
| 21:00 | 06:00 | 06:00 |
Seoul to UTC, for the same eight hours:
| Seoul local | UTC (January) | UTC (July) |
|---|---|---|
| 00:00 | 15:00 | 15:00 |
| 03:00 | 18:00 | 18:00 |
| 06:00 | 21:00 | 21:00 |
| 09:00 | 00:00 | 00:00 |
| 12:00 | 03:00 | 03:00 |
| 15:00 | 06:00 | 06:00 |
| 18:00 | 09:00 | 09:00 |
| 21:00 | 12:00 | 12:00 |
Two things to watch in these tables. First, the date: a UTC time in the evening is the next day in Seoul when the offset is positive — 21:00 UTC is 06:00 the next day in Seoul in January — and a Seoul time early in the morning is the previous day in UTC when the offset is positive. Second, the season: the January and July columns are identical, because the offset never changes. The UTC to Seoul page has the full 24-hour table.
Daylight saving and the difference
Seoul does not observe daylight saving, so the difference from UTC is constant: UTC+09:00 on every day of the year. South Korea last observed daylight saving in 1988, for the Seoul Olympics. It has not been used since. That constancy is an advantage for scheduling — the difference never moves — but it also means the difference between Seoul and any place that does observe daylight saving moves twice a year, when the other place changes its clocks. The difference between Seoul and New York, for example, is 14 hours ahead in January and 13 hours ahead in July.
What the difference means for scheduling
For a team that works in UTC — software, aviation, science — the difference is the number you add to every UTC time to get Seoul time, and the number you subtract from every Seoul time to get UTC. The mistake is to use one number all year when there are two. The safe habit is to put the UTC time in every invitation as well as the local time, and to let the calendar do the conversion: a calendar event set in UTC moves correctly when daylight saving changes, and an event set in local time does not always.
For comparison, two other major cities: London is the same time UTC in January and 1 hour ahead UTC in July, and Tokyo is 9 hours ahead UTC all year. Seoul's difference of 9 hours ahead (January) sits between them in the sense that matters for scheduling: a meeting at 14:00 UTC is 23:00 in Seoul, 14:00 in London and 23:00 in Tokyo in January. The time in Seoul page has the working-hours tables, and the meeting planner finds the overlap for any pair of cities.
Seoul vs UTC: the numbers at a glance
| Fact | Value |
|---|---|
| Standard offset | UTC+09:00 |
| Daylight saving offset | — does not observe daylight saving |
| Offset in January 2026 | UTC+09:00 |
| Offset in July 2026 | UTC+09:00 |
| Difference from UTC in January | 9 hours ahead |
| Difference from UTC in July | 9 hours ahead |
| IANA time zone | Asia/Seoul |
| Country | South Korea |
Adjusting to the difference — travel and jet lag
Travelling to Seoul from London means setting your watch forward by 9 hours in January — you lose time going east, and the first day feels short. Travelling the other way, from Seoul to London, you gain the hours back. The rule of thumb for jet lag is that it takes about a day to adjust for each hour of difference when travelling east, and a little less when travelling west — so a trip from London to Seoul in January takes most travellers about 9 days to fully adjust to, while the return trip is usually easier. The practical advice is the same in both directions: get sunlight in the morning at your destination, avoid naps longer than 20 minutes, and do not schedule important meetings for the first morning after you arrive.
The same arithmetic applies to remote work. If you are in Seoul and your team works in UTC, your working day of 09:00–17:00 local time is 00:00–08:00 UTC in January — so a stand-up at 09:00 UTC is 18:00 for you, and a stand-up at 16:00 UTC is 01:00. If those times are outside your working day, the meeting is in the wrong place in the day, and the fix is to move the UTC time, not to ask one person to work at midnight. The meeting time finder finds the hours that work for a whole team, and the time in Seoul page has the working-hours tables.
Frequently asked questions
How many hours is Seoul ahead of UTC?
Seoul is 9 hours ahead UTC in January and 9 hours ahead UTC in July. The difference is the same all year.
Is Seoul ahead of or behind UTC?
Seoul is ahead of UTC — its offset is positive (UTC+09:00 in January), so local time is later than UTC.
Does the time difference between Seoul and UTC change?
No. Seoul does not observe daylight saving, so the difference of 9 hours ahead never changes.
What is Seoul's UTC offset?
Seoul's standard offset is UTC+09:00, all year. Its IANA time zone is Asia/Seoul.
When it is midnight UTC, what time is it in Seoul?
It is 09:00 in January and 09:00 in July — the same day, because the offset is positive.
Sources
- IANA Time Zone Database, via Node.js Intl (
Intl.DateTimeFormatwithtimeZone) — offsets, daylight saving dates and local times in this article were worked out from the IANA database, not typed from memory. - TimeFlow's own time-zone data (
data/cities.ts,data/dst.ts), computed from the IANA database. - TimeFlow's UTC converter and world clock — the live tools behind the numbers on this page.
- Time-zone and daylight saving rules are set by governments and can change. For flights, deadlines and meetings that cannot move, confirm the time with an official source.