PST to EST: three hours, and the one week a year it breaks
The gap between the US west and east coasts is three hours almost always — and the exception is short, predictable, and the reason a recurring call slips.
The short answer
Add 3 hours. 9am Pacific is 12pm Eastern. 1pm Pacific is 4pm Eastern.
This holds all year, because both coasts change their clocks on the same dates. New York runs 3 hours ahead of Los Angeles in January and 3 hours ahead in July. The exception is not the gap: it is that for part of the year the correct labels are PDT and EDT, not PST and EST.
The conversion table
| Pacific | Eastern | Pacific | Eastern | |
|---|---|---|---|---|
| 6:00 | 9:00 | 12:00 | 15:00 | |
| 7:00 | 10:00 | 13:00 | 16:00 | |
| 8:00 | 11:00 | 14:00 | 17:00 | |
| 9:00 | 12:00 | 15:00 | 18:00 | |
| 10:00 | 13:00 | 16:00 | 19:00 | |
| 11:00 | 14:00 | 17:00 | 20:00 |
Anything from 9pm Pacific onward lands on the next day Eastern: 9pm Pacific is midnight Eastern, and 10pm Pacific is 1am the following morning in New York. That is the part people miss when they schedule late.
Why three hours is so reliable
Both zones sit in the United States and follow the same federal daylight-saving schedule. When the Pacific coast springs forward, so does the Eastern coast, on the same night. The offsets both shift by an hour, so the difference between them never moves.
| Pacific | Eastern | Gap | |
|---|---|---|---|
| Winter | PST · UTC−8 | EST · UTC−5 | 3 hours |
| Summer | PDT · UTC−7 | EDT · UTC−4 | 3 hours |
So what actually breaks?
Two things, and neither is the arithmetic.
1. The labels stop being true. For roughly eight months a year the zones are on daylight time — PDT and EDT. “3pm PST” in June is not a real time. If you are converting from a written offset rather than from a city, you will be an hour out. This is the single most common time zone error in scheduling, and it has its own page.
2. Anyone outside the US changes on different dates. The US and the EU do not switch on the same weekends. If your call also includes London or Berlin, the three-hour PST↔EST gap stays fixed while the transatlantic gap moves — for a few weeks each spring and autumn. See Eastern Time to GMT.
The safe way to write it
Write the city, not the abbreviation: “10am Los Angeles / 1pm New York.” It is correct in every month and needs no footnote. If you must use a short form, PT and ET are safe year-round because they do not claim a specific offset.
Arizona, briefly
If a third participant is in Phoenix, the neat three-hour rule stops applying. Arizona does not observe daylight saving, so its gap to New York is 2 hours ahead in winter and 3 hours ahead in summer. Same two cities, different answer by season, with Arizona doing nothing at all.
Related: EST vs EDT · EST to PST · 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.