EST to PST: subtract three hours
Going east to west you lose three hours — which is why a 9am East Coast call is a 6am West Coast call, and why nobody on the west end enjoys it.
The short answer
Subtract 3 hours. 12pm Eastern is 9am Pacific. 9am Eastern is 6am Pacific.
Los Angeles runs 3 hours behind New York in January and 3 hours behind in July — both coasts change their clocks together, so the difference is constant.
The table
| Eastern | Pacific | Eastern | Pacific | |
|---|---|---|---|---|
| 8:00 | 5:00 | 14:00 | 11:00 | |
| 9:00 | 6:00 | 15:00 | 12:00 | |
| 10:00 | 7:00 | 16:00 | 13:00 | |
| 11:00 | 8:00 | 17:00 | 14:00 | |
| 12:00 | 9:00 | 18:00 | 15:00 | |
| 13:00 | 10:00 | 02:00 | 23:00 prev. day |
Anything before 3am Eastern lands on the previous day in California.
The real problem is not the maths
Three hours is easy to compute and hard to live with, because it eats the overlap from both ends.
A standard 9-to-5 working day on each coast leaves a shared window of roughly noon to 5pm Eastern — 9am to 2pm Pacific. Five hours, in the middle of one day and the start of the other. Everything outside it is somebody's early morning or somebody's evening.
This is why:
- East coast teams schedule "first thing" meetings that the west coast experiences as 6am.
- West coast teams schedule "end of day" reviews that land at 8pm in New York.
- The 9am Eastern standup is the single most complained-about recurring meeting in American companies with two offices.
None of that is a conversion error. It is a genuine constraint, and the only fix is deciding — explicitly — who absorbs the inconvenience, rather than letting the calendar decide by default. There is a scenario about exactly this.
Labels, again
For most of the year the correct abbreviations are EDT and PDT. “9am EST” in August is not a real time. Use ET / PT, or write the cities. See EST vs EDT.
The two zones in between
Travelling east to west the US passes through four zones:
| Zone | Behind Eastern |
|---|---|
| Eastern (New York) | — |
| Central (Chicago) | 1 hour |
| Mountain (Denver) | 2 hours |
| Pacific (Los Angeles) | 3 hours |
Arizona is the exception to watch: it is on Mountain time but does not observe daylight saving, so for half the year it matches Denver and for the other half it matches Los Angeles.
Related: PST to EST · CST to EST
Timezone: World Clock Widget
A world clock, converter and live day/night map for iPhone — 325 cities, offline, no account.
Figures on this page are computed from the IANA time zone database. Last generated 2026-08-18.