America/Los_Angeles

TZ identifier and aliases

America/Los_Angeles is the canonical identifier for US Pacific Time. The older US/Pacific name and the POSIX-style PST8PDT both still resolve to the same rules on most systems but are deprecated aliases — new code, cron jobs and TZ environment variables should reference America/Los_Angeles directly rather than either legacy form.

UTC offset and DST rule

Pacific Time is -08:00 (PST) on standard time and -07:00 (PDT) during daylight saving. Under the current US rule (Energy Policy Act of 2005, effective since 2007), DST runs from the second Sunday in March to the first Sunday in November — March 8 to November 1 in 2026. For the other eight months of the year, the zone sits eight hours behind UTC.

Using it in cron, CI and Postgres

Set TZ=America/Los_Angeles for a process that needs to schedule against Pacific local time. Postgres accepts the identifier directly — SET TIME ZONE 'America/Los_Angeles'; or the timezone config parameter — and correctly applies the DST rule for any timestamp, rather than a fixed offset that would drift wrong twice a year. Some cron implementations (Vixie-cron, some container schedulers) support a CRON_TZ=America/Los_Angeles line at the top of a crontab; GitHub Actions' schedule: trigger always evaluates in UTC regardless, so a job meant to run at a fixed Pacific hour needs its UTC equivalent updated by hand across the spring/fall boundary, or computed at runtime instead of hardcoded in the cron expression. As with any DST-observing zone, avoid scheduling anything for 2:00–3:00am local time: on the March transition that local time doesn't exist, so a matching cron expression silently never fires that day; on the November transition it occurs twice, so a naive scheduler can run the job twice.

History and quirks

Pacific Time became one of the four original US time zones the railroads established in 1883, formalized in federal law by the Standard Time Act of 1918. California and most of the Pacific coast have observed daylight saving continuously since the Uniform Time Act of 1966 standardized DST nationally (aside from the WWII-era "War Time" period of year-round advanced clocks from 1942–1945) — unlike Arizona, its neighbor to the east, Los Angeles has never opted out. The zone's UTC offset, -08:00, also happens to define Pacific Standard Time for aviation and maritime use across the US West Coast, and its DST-adjusted -07:00 briefly coincides with Mountain Standard Time (Arizona's permanent offset) every summer — a common source of "is it the same time in LA and Phoenix right now" confusion, since the answer flips between yes and no depending on the calendar date.

Offsets and DST transitions on this page are computed from the IANA time zone database bundled with your browser; the rules described above were verified against tzdata 2026b when this page was published.