Greenwich time on the West Coast
Pacific time is eight hours behind GMT in winter and seven hours behind in summer. 16:00 GMT is 8:00 AM in Los Angeles in January and 9:00 AM in July. Enter your GMT time or press Use now to see the Pacific equivalent.
If you are working from a GMT announcement, such as a product launch or a livestream, check what the organiser means. GMT is a fixed zone; London is on British Summer Time in summer, an hour ahead. A 6:00 PM London start in July is 17:00 GMT, which is 10:00 AM in San Francisco.
The West Coast sees GMT times in the early morning and overnight. A 9:00 to 17:00 GMT workday runs 1:00 AM to 9:00 AM Pacific in January, so only the last hours of the UK day overlap the start of the Pacific one. The hour-by-hour table shows the full day on the Pacific clock, and it moves by one hour in summer.
Because the gap is large, the date often changes. 6:00 AM GMT is 10:00 PM the previous evening in January. The result says so. Use swap to go from Pacific back to GMT.
Worked examples
Questions about this tool
How many hours is PST behind GMT?
Eight hours in winter and seven hours in summer, when the Pacific coast moves to daylight time.
What is the best GMT hour for a call with the West Coast?
Late GMT afternoon, around 16:00 to 17:00, is 8:00 to 9:00 AM on the Pacific coast in January, which is about as early as a Pacific team will agree to.
Why does the gap change in summer?
GMT does not change, but the Pacific coast moves forward an hour in spring, so the gap shrinks by one.
Related tools
Where this comes from: IANA time zone database and the rules behind it ยท RFC 6557, how the time zone database is maintained