How many hours is PST behind PHST?
As abbreviations, PHST is always 16 hours ahead of PST: PST is UTC−8 and PHST is UTC+8. To convert, add 16 hours.
Check which label you actually need: PST (Pacific Time is on PDT today). A time written with an abbreviation that is not in use is usually meant as the local time, so convert between the places instead: right now PHST is 15 hours ahead of PST.
When the PST to PHST time difference changes
For most of the year PHST is 15 hours ahead of PST. From 1 November to 31 December 2026, PHST is 16 hours ahead of PST instead, because the two places change their clocks on different dates. Meetings booked by the usual gap land an hour off in those weeks.
| Dates | PHST vs PST | Length |
|---|---|---|
| 8 March 2026 to 31 October 2026 | 15 hours ahead | 238 days |
| 1 November 2026 to 31 December 2026 | 16 hours ahead | 61 days |
| 1 January 2027 to 13 March 2027 | 16 hours ahead | 72 days |
| 14 March 2027 to 6 November 2027 | 15 hours ahead | 238 days |
| 7 November 2027 to 31 December 2027 | 16 hours ahead | 55 days |
Calling hours for PST and PHST
- When PHST is 15 hours ahead of PST: no shared 09:00 to 17:00 hours; try 17:00 in PST (08:00 in PHST).
- When PHST is 16 hours ahead of PST: no shared 09:00 to 17:00 hours; try 17:00 in PST (09:00 in PHST).