When a San Francisco office opens at 9:00 AM, New York desks have already been buzzing for three hours. That gap is locked: Pacific Standard Time (UTC-8) sits exactly 3 hours behind Eastern Standard Time (UTC-5). Noon in Los Angeles, 3:00 PM in Washington. The offset does not shift with the seasons, even if the letter codes do.
PST to EST: 3 Hours Behind
Pacific Standard Time is UTC-8. Eastern Standard Time is UTC-5. Subtract three hours from Eastern and you land on Pacific.
That means:
- 9:00 AM PST → 12:00 PM EST
- 12:00 PM PST → 3:00 PM EST
- 5:00 PM PST → 8:00 PM EST
The reverse: subtract three hours from Eastern to get Pacific. 4:00 PM EST is 1:00 PM PST.
When PST and EST Apply (Winter vs. Summer)
The abbreviations change with the seasons. Most people get this wrong.
Winter (early November to mid-March): - Pacific Standard Time (PST), UTC-8 - Eastern Standard Time (EST), UTC-5
Summer (mid-March to early November): - Pacific Daylight Time (PDT), UTC-7 - Eastern Daylight Time (EDT), UTC-4
The 3-hour gap stays identical. But saying "EST" in July is technically wrong: it is EDT. This is the single most common time zone error Americans make. If someone in New York says "I'll call you at 3 PM EST" in July, they really mean EDT.
PDT to EDT: The Summer Difference
In summer, both zones spring forward. PDT is UTC-7, EDT is UTC-4. The math does not change: Eastern is still 3 hours ahead.
Summer example: 2:00 PM PDT → 5:00 PM EDT.
Winter example: 2:00 PM PST → 5:00 PM EST.
Same clock reading, different labels. The 3-hour gap is constant year-round.
Common Conversion Examples
| Pacific Time | Eastern Time | Notes |
|---|---|---|
| 6:00 AM | 9:00 AM | NYSE opens; West Coast traders are at their desks |
| 8:00 AM | 11:00 AM | Regular workday start on both coasts |
| 12:00 PM | 3:00 PM | Midday |
| 3:30 PM | 6:30 PM | East Coast offices winding down |
| 9:00 PM | 12:00 AM | Late evening, East Coast past midnight |
Calling East Coast From West Coast: Timing Tips
The 3-hour gap creates real decisions.
Calling East from California: 8:00 AM PT is 11:00 AM ET. Most East Coast offices open by 9:00 AM ET, so anything after 6:00 AM PT is safe. The sweet spot: 9:00 AM to 11:00 AM PT (noon to 2:00 PM ET).
Calling West from New York: 5:00 PM ET is 2:00 PM PT. Do not call after 7:00 PM ET (4:00 PM PT) if you want to catch someone before they log off. West Coast workers often start later, so early afternoon Pacific time is ideal.
What to skip: Do not schedule a 4:00 PM ET call with California expecting them to be near end-of-day. They are mid-afternoon. And never call California at 6:00 PM ET thinking the workday is over. It is not.
The real trap is the reverse: East Coasters calling at 4:45 PM PT (7:45 PM ET) get voicemail. West Coasters calling at 7:00 AM PT (10:00 AM ET) are fine.
Quick Conversion Table
| Pacific (PT) | Eastern (ET) | Time of Day |
|---|---|---|
| 5:00 AM | 8:00 AM | Early start |
| 7:00 AM | 10:00 AM | Standard East Coast opening |
| 9:00 AM | 12:00 PM | Late morning |
| 12:00 PM | 3:00 PM | Midday |
| 2:30 PM | 5:30 PM | East Coast close |
| 6:00 PM | 9:00 PM | Evening |
The 30-Second Cheat Sheet
- PST to EST: Add 3 hours.
- EST to PST: Subtract 3 hours.
- PDT to EDT: Add 3 hours.
- EDT to PDT: Subtract 3 hours.
- The gap never changes. Not for DST, not for holidays.
- "EST" in summer is wrong. Use EDT or just say "Eastern Time."
- Best time to call East from West: 9:00 AM, 11:00 AM PT.
- Best time to call West from East: 12:00 PM, 3:00 PM ET.
The 3-hour gap shapes everything: when markets open (6:30 AM PT), when TV airs (8:00 PM ET is 5:00 PM PT), and when to pick up the phone. Get the math right once, and you are set for the year.
For more details on how each zone works, see the Pacific Time Zone guide, the Eastern Time Zone overview, or the best times to call across US time zones.