Key facts
London is always 8 hours ahead of Pacific time. PST (UTC-8) in winter and PDT (UTC-7) in summer 鈥?both map to an 8-hour London lead because the UK also shifts clocks in spring (GMT 鈫?BST). The gap is stable year-round except during the brief transition weeks in late March and late October.
The working-hours overlap window is 6 AM to 9 AM Pacific (2 PM to 5 PM London). Outside this window, one side is outside business hours.
Understanding the gap: PST, PDT, GMT, and BST
The US West Coast observes two time zones across the year:
- PST 鈥?Pacific Standard Time (UTC-8): First Sunday of November to second Sunday of March
- PDT 鈥?Pacific Daylight Time (UTC-7): Second Sunday of March to first Sunday of November
London also shifts twice per year:
- GMT 鈥?Greenwich Mean Time (UTC+0): Last Sunday of October to last Sunday of March
- BST 鈥?British Summer Time (UTC+1): Last Sunday of March to last Sunday of October
Because both zones shift by one hour in the same direction in spring, the gap stays at 8 hours throughout the year. PST (UTC-8) and GMT (UTC+0): 8 hours. PDT (UTC-7) and BST (UTC+1): also 8 hours. The arithmetic works out identically.
The transition-week exception
The US switches to PDT in mid-March; the UK switches to BST about a week later. During that week, the gap is temporarily 7 hours (PDT + GMT). In late October, the UK reverts to GMT before the US reverts to PST, creating a temporary 9-hour gap. For calls scheduled in these windows, always verify using the tool on this page or the Meeting Time Finder.
Best meeting hours for PST and London
Standard business hours are 9 AM to 5 PM in both locations. The overlap window where both cities are within those hours:
6:00 AM 鈥?9:00 AM Pacific (2:00 PM 鈥?5:00 PM London)
3-hour window 路 requires early Pacific start 路 comfortable London afternoon
The most popular single slot is 8 AM PST / 4 PM London. It gives the Pacific side a reasonable early start, and London colleagues have a full hour before end of day to act on anything discussed.
After 9 AM Pacific, London is outside standard working hours. Any call after 9 AM PST requires explicit agreement from London participants to work late.
Hour-by-hour PST to London conversion
All hours shown as PST/PDT 鈫?GMT/BST. London times are identical in both seasons because the zones shift together.
| PST / PDT | London GMT / BST | Within UK hours? | Page |
|---|---|---|---|
| 6:00 AM | 2:00 PM | Yes | 6 AM PST |
| 7:00 AM | 3:00 PM | Yes | 7 AM PST |
| 8:00 AM | 4:00 PM | Yes 鈥?Most popular | 8 AM PST |
| 9:00 AM | 5:00 PM | End of day | 9 AM PST |
| 10:00 AM | 6:00 PM | No | 10 AM PST |
| 11:00 AM | 7:00 PM | No | 11 AM PST |
| 12:00 PM | 8:00 PM | No | 12 PM PST |
| 1:00 PM | 9:00 PM | No | 1 PM PST |
| 2:00 PM | 10:00 PM | No | 2 PM PST |
| 3:00 PM | 11:00 PM | No | 3 PM PST |
| 4:00 PM | 12:00 AM | No | 4 PM PST |
| 5:00 PM | 1:00 AM | No | 5 PM PST |
Common scheduling mistakes 鈥?PST and London
Booking a 10 AM Pacific call without checking
10 AM PST is 6 PM London 鈥?after working hours. Teams frequently book these by mistake because 10 AM feels like a reasonable morning start. Always verify the London time before sending any calendar invite.
Not adjusting for the transition weeks
In late March and late October, the US and UK switch clocks on different dates. A recurring 8 AM PST meeting may temporarily show a different London time on those weeks. Build a calendar reminder to recheck recurring meetings around the last Sunday of March and the last Sunday of October.
Writing PST in summer invites
From March to November, the US West Coast is on PDT, not PST. Writing "PST" in a summer invite can confuse recipients who apply the wrong offset. Always write the full date alongside both city times: "8 AM PDT / 4 PM BST, 14 August".
Expecting London to be flexible after 9 AM Pacific
After 9 AM PST, London is past 5 PM. While some global teams agree to occasional late calls, making this a recurring expectation without explicit agreement will cause friction. Rotate the burden or use asynchronous workflows for anything after the 9 AM PST cut-off.
Frequently asked questions
How many hours ahead is London from PST?
London is 8 hours ahead of Pacific Standard Time (PST) and 8 hours ahead of Pacific Daylight Time (PDT). The gap is constant through the year because both zones observe daylight saving time and shift by the same amount in spring.
Does the PST to London gap change in summer?
No 鈥?both zones shift forward by one hour in spring, maintaining the 8-hour difference. The only exceptions are the brief windows in late March and late October when one zone has switched and the other has not yet.
What is 8 AM PST in London?
8 AM PST is 4 PM GMT (winter) or 4 PM BST (summer) in London. This is the most commonly scheduled Pacific-to-London meeting slot.
What PST times fall outside London business hours?
Any Pacific time after 9 AM PST falls outside the standard UK working day. 10 AM PST is 6 PM London, and each hour after that moves further into the UK evening.