Convert PST to GMT
To convert PST to GMT: 9:00 AM PST is 5:00 PM GMT. PST is UTC-08:00 and GMT is UTC+00:00, so GMT is 8 hours ahead of PST, but not all year, as explained below.
In Greenwich Mean Time
- On a 24-hour clock
- 09:00 PST is 17:00 GMT
- The offsets
- PST is UTC-08:00, GMT is UTC+00:00
- Difference
- GMT is 8 hours ahead of PST
- Date
- Same calendar day.
- This gap does NOT hold all year Convert through the offset in force on the date you care about.
- The two ends switch on different dates, or one does not switch at all.
- PST is only in force part of the year United States: daylight time starts the second Sunday in March, at 02:00 local time and ends the first Sunday in November, at 02:00 local time (Energy Policy Act of 2005, in force since 2007). In 2026 that is 2026-03-08 to 2026-11-01. Los Angeles is on PDT between those dates.
- otherwise PDT, UTC-07:00
- Military time zone letters Z (Zulu) is UTC. A to M run east of Greenwich an hour apart, N to Y west, and J is left out. A letter names an offset, so a zone that switches to daylight time changes letter: EST is R, EDT is Q.
- PST is U (Uniform), GMT is Z (Zulu)
- In Zulu notation Four digits on a 24-hour clock, no colon, then Z for UTC.
- 1700Z
- In every zone
- HST 07:00 AKST 08:00 PST 09:00 AKDT 09:00 MST 10:00 PDT 10:00 CST 11:00 MDT 11:00 EST 12:00 CDT 12:00 EDT 13:00 UTC 17:00 GMT 17:00 BST 18:00 CET 18:00 CEST 19:00 EET 19:00 EEST 20:00 MSK 20:00 IST 22:30 SGT 01:00 HKT 01:00 JST 02:00 AEST 03:00 AEDT 04:00 NZST 05:00 NZDT 06:00
How the Time Zone Converter works
Pacific Standard Time (PST) is UTC-08:00 and Greenwich Mean Time (GMT) is UTC+00:00, so converting PST to GMT means adding 8 hours to the PST time. GMT is 8 hours ahead of PST.
Worked through: 9:00 AM PST is 5:00 PM GMT.
The gap between these two is not the same all year, which is the thing to get right. the two zones switch on different dates (PST under the United States rule and GMT under the European Union and United Kingdom one), so the difference moves. Convert through the offset in force on the date you care about rather than through the abbreviation somebody typed; the offsets above are definitions and the abbreviation is a claim about the calendar.
Eight hours forward, the widest gap in regular commercial use between two heavily populated zones, and the one that produces the famous non-overlap: 09:00 in San Francisco is 17:00 in London, so the working days touch for about an hour. Teams split across these two zones either accept a single daily overlap window or stop trying to hold synchronous meetings, which is why so much asynchronous working culture came out of exactly this pairing.
One thing worth stating plainly, because it is the most common mistake in this whole subject: an abbreviation is not a place. PST is Pacific Standard Time, which Los Angeles uses only part of the year; the rest of the time it is on PDT at UTC-07:00. GMT is likewise only in force for part of the year in London and Dublin in winter; otherwise it is BST at UTC+01:00. If what you have is a city and a date rather than a pair of abbreviations, that is a different question and needs the tz database, not arithmetic. This is also why the shifting designations exist: PT means Pacific time whichever of the two is in force. Searching for PT and searching for PST to GMT are the same question in two vocabularies, which is why this converter answers both.
Common times for this pair:
- 8:00 AM PST is 4:00 PM GMT - 9:00 AM PST is 5:00 PM GMT - 10:00 AM PST is 6:00 PM GMT - 4:00 PM PST is 12:00 AM GMT the next day
Time Zone Converter FAQ
What is the time difference between PST and GMT?
GMT is 8 hours ahead of PST. PST is UTC-08:00 and GMT is UTC+00:00, and both offsets are definitions rather than measurements, so the subtraction is exact.
What time is 9:00 AM PST in GMT?
9:00 AM PST is 5:00 PM GMT. Add 8 hours and carry the date if it crosses midnight.
Does the difference between PST and GMT change with daylight saving?
Yes, and this is the main thing to watch on this pair. the two switch under different rules and on different dates, so the difference takes more than one value across the year. In 2026 the United States switch runs from 2026-03-08 to 2026-11-01.
Is there anything specific to this pair worth knowing?
Eight hours forward, the widest gap in regular commercial use between two heavily populated zones, and the one that produces the famous non-overlap: 09:00 in San Francisco is 17:00 in London, so the working days touch for about an hour. Teams split across these two zones either accept a single daily overlap window or stop trying to hold synchronous meetings, which is why so much asynchronous working culture came out of exactly this pairing.
Someone wrote PST but it is summer. What do they mean?
Almost certainly the zone rather than the abbreviation: Los Angeles time, which in summer is PDT at UTC-07:00 rather than PST at UTC-08:00. People type the standard-time abbreviation all year round. If an invitation is an hour out from what you calculated, this is why.