How to read it
London and San Francisco, side by side
Each row is one city's day, half an hour to a square, lined up by the hours along the bottom.
- 1Filled: at the desk, 9:00 to 18:00 where that city is.
- 2Grey: up early, up late, or the weekend.
- 3Outline: asleep.
- 4Red band: your slot. Read straight down to see the same moment in every city.
- 5A marks the best time for everyone; B, when there is one, the next best.
The red band is the best time to call on Wed, 21 Oct 2026: 17:00–18:00 in London, which is 09:00–10:00 in San Francisco.
Through the year
How the gap between London and San Francisco moves
San Francisco is 8h behind London today. Daylight saving moves it:
- San Francisco 8h behind London
- San Francisco 7h behind London
- Sun, 25 Oct 2026 London's clocks go back an hour. San Francisco is then 7h behind London.
- Sun, 1 Nov 2026 San Francisco's clocks go back an hour. San Francisco is then 8h behind London.
- Sun, 14 Mar 2027 San Francisco's clocks go forward an hour. San Francisco is then 7h behind London.
- Sun, 28 Mar 2027 London's clocks go forward an hour. San Francisco is then 8h behind London.
Hour by hour
London to San Francisco time, hour by hour
On a working day (Wed, 21 Oct 2026), with working hours of 9:00 to 18:00 in both cities.
- London starts work 09:00 01:00 in San Francisco Asleep
- San Francisco starts work 09:00 17:00 in London At desk
- London finishes work 18:00 10:00 in San Francisco At desk
- San Francisco finishes work 18:00 02:00 Wed in London Asleep
Show all 24 hours
| London | San Francisco |
|---|---|
| 00:00 Asleep | 16:00 Tue At desk |
| 01:00 Asleep | 17:00 Tue At desk |
| 02:00 Asleep | 18:00 Tue Late |
| 03:00 Asleep | 19:00 Tue Late |
| 04:00 Asleep | 20:00 Tue Late |
| 05:00 Asleep | 21:00 Tue Late |
| 06:00 Asleep | 22:00 Tue Asleep |
| 07:00 Early | 23:00 Tue Asleep |
| 08:00 Early | 00:00 Asleep |
| 09:00 At desk | 01:00 Asleep |
| 10:00 At desk | 02:00 Asleep |
| 11:00 At desk | 03:00 Asleep |
| 12:00 At desk | 04:00 Asleep |
| 13:00 At desk | 05:00 Asleep |
| 14:00 At desk | 06:00 Asleep |
| 15:00 At desk | 07:00 Early |
| 16:00 At desk | 08:00 Early |
| 17:00 At desk | 09:00 At desk |
| 18:00 Late | 10:00 At desk |
| 19:00 Late | 11:00 At desk |
| 20:00 Late | 12:00 At desk |
| 21:00 Late | 13:00 At desk |
| 22:00 Asleep | 14:00 At desk |
| 23:00 Asleep | 15:00 At desk |
Questions
Questions people ask
What is the time difference between London and San Francisco?
San Francisco is 8h behind London (as of Wed, 21 Oct 2026). That changes on Sun, 25 Oct 2026, when London's clocks go back: then San Francisco is 7h behind London.
What is the best time for a call between London and San Francisco?
On a working day, the best time for a call is 17:00–18:00 in London (09:00–10:00 in San Francisco) until 24 Oct 2026 and from 1 Nov 2026 to 13 Mar 2027 and from 28 Mar 2027, and 16:00–17:00 in London (09:00–10:00 in San Francisco) from 25 Oct 2026 to 31 Oct 2026 and from 14 Mar 2027 to 27 Mar 2027.
Does London change its clocks?
Yes. London moves its clocks back an hour on Sun, 25 Oct 2026, and forward an hour on Sun, 28 Mar 2027.
Does San Francisco change its clocks?
Yes. San Francisco moves its clocks back an hour on Sun, 1 Nov 2026, and forward an hour on Sun, 14 Mar 2027.
More city pairs
Compare more cities
London and…
- London and Mumbai
- London and Delhi
- London and Bengaluru
- London and Dubai
- London and Abu Dhabi
- London and Riyadh
- London and Doha
- London and Singapore
- London and Hong Kong
- London and Tokyo
- London and Sydney
- London and Paris
- London and Berlin
- London and Amsterdam
- London and New York
- London and Toronto
- London and Chicago
- London and Los Angeles
San Francisco and…
- San Francisco and Mumbai
- San Francisco and Delhi
- San Francisco and Bengaluru
- San Francisco and Dubai
- San Francisco and Abu Dhabi
- San Francisco and Riyadh
- San Francisco and Doha
- San Francisco and Singapore
- San Francisco and Hong Kong
- San Francisco and Tokyo
- San Francisco and Sydney
- San Francisco and Paris
- San Francisco and Berlin
- San Francisco and Amsterdam
- San Francisco and New York
- San Francisco and Toronto
- San Francisco and Chicago
- San Francisco and Los Angeles
From the team behind 10:10
Running an event across time zones?
C4E has spent twenty years running conferences, dealer meets and offsites in more than 40 countries, with clients, speakers and crews in different time zones. 10:10 is one of the tools we built for our own shows. It is free, with no account and nothing upsold.