Short answer
PST (Pacific Standard Time, UTC−8) is the US West Coast's winter time and PDT (Pacific Daylight Time, UTC−7) its summer time. Right now Los Angeles is on PST (UTC−8). The next switch is on Sunday 14 March 2027. Writing PT, for Pacific Time, covers both.
Both labels describe the same clock in California, Washington and Oregon. It runs one hour later for most of the year, and the label tells the reader which of the two settings you mean.
PST and PDT side by side
| PST | PDT | |
|---|---|---|
| Full name | Pacific Standard Time | Pacific Daylight Time |
| Offset from UTC | UTC−8 | UTC−7 |
| ISO 8601 suffix | −08:00 | −07:00 |
| In use in the US and Canada | First Sunday in November to second Sunday in March | Second Sunday in March to first Sunday in November |
| Glossary | PST | PDT |
PDT is one hour ahead of PST. Noon PST is 20:00 UTC; noon PDT is 19:00 UTC.
Which one applies today
Right now Los Angeles is on PST, UTC−8. The West Coast follows the national US rule: clocks go forward one hour at 02:00 local time on the second Sunday in March, and back one hour at 02:00 on the first Sunday in November. That puts the Pacific coast on PDT for a little under eight months of the year and on PST for the rest.
The next change is Sunday 14 March 2027 at 02:00, when clocks go forward one hour. In 2027 the clocks go forward on Sunday 14 March 2027 and back on Sunday 7 November 2027. The US daylight saving page lists the dates for the years after that.
The East Coast switches on the same Sundays, at 02:00 its own local time, so it changes three hours before the West Coast does. The mechanics, including the hour that happens twice in November, are the same as in EST vs EDT.
Where Pacific Time is used
In the United States:
- California, all of it, including Los Angeles, San Francisco and San Diego.
- Washington, all of it, including Seattle.
- Oregon, apart from most of Malheur County in the east, which uses Mountain Time.
- Nevada, including Las Vegas and Reno, apart from a few border towns such as West Wendover.
- Northern Idaho, the panhandle around Coeur d'Alene. The rest of Idaho is on Mountain Time.
In Canada, most of British Columbia uses Pacific Time, including Vancouver and Victoria, and switches on the US dates. Yukon used Pacific Time until 2020 and now stays at UTC−7 all year.
In Mexico, the state of Baja California uses Pacific Time. Tijuana follows the US switch dates, which keeps it in step with San Diego across the border.
Alaska and Hawaii are not on Pacific Time. Alaska has its own zone, one hour behind the West Coast, and Hawaii stays at UTC−10 all year.
Why the West Coast says "PT"
Plenty of people write PST all year. In July, "10:00 PST" strictly means 10:00 at UTC−8, which is 11:00 on California clocks. People usually guess the intent. Software and anyone converting by hand do not: a time parsed as a fixed PST offset is an hour off from March to November.
PT, or Pacific Time, avoids the problem. It means PST in winter and PDT in summer, whichever applies on the day. For a product launch, a contract or a log line where the minute matters, add the offset too: "10:00 PT (UTC−7)".
Arizona is not on Pacific Time
Arizona sits next to California but uses Mountain Standard Time, UTC−7, and does not change its clocks. In summer that gives Phoenix the same clock time as Los Angeles, because PDT is also UTC−7. In winter Phoenix is one hour ahead. Right now Phoenix is ahead of Los Angeles. If you write "PT" for an Arizona meeting it will be right in summer and wrong in winter, so say "Arizona time" instead.
PST can also mean Philippine Standard Time
The Philippines calls its own time Philippine Standard Time, UTC+8, and it is often shortened to PST, or PhST. The site's glossary lists it as PHT. It has nothing to do with California: Manila is 16 hours ahead of Los Angeles right now. The Philippines does not use daylight saving time, so the gap is 15 hours while California is on PDT and 16 hours while it is on PST.
If a message says "PST" and the sender is in Manila or works with a team there, check which one they mean before you book anything. Writing PT for California and PHT, or "Manila time", for the Philippines removes the doubt.
Converting Pacific Time
- New York is 3 hours ahead of Los Angeles all year, because both change on the same Sundays. Only for a few hours on the night of the change is the gap different.
- London is usually 8 hours ahead. For a few weeks in March and about a week around the end of October it is 7, because the UK changes its clocks on different dates. A 09:00 meeting in Los Angeles is 17:00 in London today.
- India is 13 hours 30 minutes ahead today. India does not change its clocks, so the gap is 12 hours 30 minutes during PDT and 13 hours 30 minutes during PST. The IST to PST converter works out any time.
In software, store times in UTC and convert with the IANA zone name America/Los_Angeles rather than a fixed PST offset. The zone carries every past and future switch date as far as they are known.
Frequently asked questions
Is California on PST or PDT right now?
California is on PST (UTC−8). The next switch is on Sunday 14 March 2027.
What is the difference between PST and PT?
PST is one fixed offset, UTC−8, used in winter. PT, Pacific Time, is the name of the zone and means PST or PDT, whichever is in use on the day.
Is PST 3 hours behind EST?
Yes. PST (UTC−8) is 3 hours behind EST (UTC−5), and PDT is 3 hours behind EDT. Los Angeles and New York stay 3 hours apart all year.
Is PDT ahead of PST?
Yes, by one hour. Clocks on PDT read one hour later than they would on PST.
Is Philippine Standard Time the same as PST?
No. Philippine Standard Time is UTC+8, 16 hours ahead of Pacific Standard Time. Both are sometimes shortened to PST, so check the context.