Observatory log
London and Ulsan, compared
- 01Difference now
Ulsan is 8 hours ahead of London.
London: BST (UTC+1) · Ulsan: KST (UTC+9)
Next changeFrom 25 October 2026: Ulsan is 9 hours ahead of London.
- 02Through 2026–2027
- 1 January 2026 – 29 March 2026+9 h
- 29 March 2026 – 25 October 2026+8 h
- 25 October 2026 – 28 March 2027+9 h
- 28 March 2027 – 31 October 2027+8 h
- 31 October 2027 – 31 December 2027+9 h
Difference of Ulsan from London. It changes on the days either place changes its clocks (dates local to that place).
- 03Shared working hours
Their working days never overlap.
Counted as 09:00–17:00 local time on each place’s own working days, for the next seven days.
- 04Best time to meet
06:00–14:00 in London = 14:00–22:00 in Ulsan
No shared office hours: this is early or late for one side (Mon–Fri).
- 05Weekend
London: Saturday and Sunday
Ulsan: Saturday and Sunday
24 hours
A day in London, in Ulsan
| London | Ulsan | Working hours, evening, night or weekend in each place |
|---|---|---|
| 00:00 | 08:00 | |
| 01:00 | 09:00 | |
| 02:00 | 10:00 | |
| 03:00 | 11:00 | |
| 04:00 | 12:00 | |
| 05:00 | 13:00 | |
| 06:00 | 14:00 | |
| 07:00 | 15:00 | |
| 08:00 | 16:00 | |
| 09:00 | 17:00 | |
| 10:00 | 18:00 | |
| 11:00 | 19:00 | |
| 12:00 | 20:00 | |
| 13:00 | 21:00 | |
| 14:00 | 22:00 | |
| 15:00 | 23:00 | |
| 16:00 | 00:00Tomorrow | |
| 17:00 | 01:00Tomorrow | |
| 18:00 | 02:00Tomorrow | |
| 19:00 | 03:00Tomorrow | |
| 20:00 | 04:00Tomorrow | |
| 21:00 | 05:00Tomorrow | |
| 22:00 | 06:00Tomorrow | |
| 23:00 | 07:00Tomorrow |
Working hoursEarly or eveningNightWeekend
Plan a meeting: London and Ulsan
More time differences with London
Questions
Asked about London and Ulsan
What is the time difference between London and Ulsan?
Ulsan is 8 hours ahead of London. This holds until 25 October 2026; then Ulsan is 9 hours ahead of London.
What is the best time for a call between London and Ulsan?
No shared office hours. The least awkward windows, early or late for one side: Mon–Fri: 06:00–14:00 in London = 14:00–22:00 in Ulsan · 8 h.
When does the time difference between London and Ulsan change?
In the next 12 months it changes on: 25 October 2026 (+9 h); 28 March 2027 (+8 h).