AST to PST Converter
PST is 4 hours behind AST. 9:00 AM AST = 5:00 AM PST.
PST is 4 hours behind AST. To convert AST to PST, subtract 4 hours from the AST time: 9:00 AM AST = 5:00 AM PST.
AST (Atlantic Time) is used in Nova Scotia, New Brunswick, PEI; Puerto Rico and the Eastern Caribbean (all year). PST (Pacific Time) is used in Los Angeles, San Francisco, Seattle, Las Vegas, Portland, Vancouver.
AST here is Atlantic Standard Time, not Arabia Standard Time. PST here means Pacific Standard Time, not Philippine Standard Time.
AST to PST time conversion table
AST to PST on 6 Nov 2026. Today's date. Highlighted rows are 9 AM–5 PM in both places.
| AST | PST | Day |
|---|---|---|
| 12:00 AM AST | 8:00 PM PST | previous day |
| 1:00 AM AST | 9:00 PM PST | previous day |
| 2:00 AM AST | 10:00 PM PST | previous day |
| 3:00 AM AST | 11:00 PM PST | previous day |
| 4:00 AM AST | 12:00 AM PST | night |
| 5:00 AM AST | 1:00 AM PST | night |
| 6:00 AM AST | 2:00 AM PST | night |
| 7:00 AM AST | 3:00 AM PST | night |
| 8:00 AM AST | 4:00 AM PST | night |
| 9:00 AM AST | 5:00 AM PST | night |
| 10:00 AM AST | 6:00 AM PST | — |
| 11:00 AM AST | 7:00 AM PST | — |
| 12:00 PM AST | 8:00 AM PST | — |
| 1:00 PM AST | 9:00 AM PST | work hours |
| 2:00 PM AST | 10:00 AM PST | work hours |
| 3:00 PM AST | 11:00 AM PST | work hours |
| 4:00 PM AST | 12:00 PM PST | work hours |
| 5:00 PM AST | 1:00 PM PST | — |
| 6:00 PM AST | 2:00 PM PST | — |
| 7:00 PM AST | 3:00 PM PST | — |
| 8:00 PM AST | 4:00 PM PST | — |
| 9:00 PM AST | 5:00 PM PST | — |
| 10:00 PM AST | 6:00 PM PST | — |
| 11:00 PM AST | 7:00 PM PST | — |
- Work rows — 9 AM–5 PM in both places
- Night in the destination (10 PM–6 AM)
How to convert AST to PST
Subtract 4 hours from the AST time to get PST.
Example: 9:00 AM AST = 5:00 AM PST.
Across midnight: 1:00 AM AST = 9:00 PM PST (previous day). The date changes, so always check the day as well as the hour.
Time difference between AST and PST
The time difference between AST and PST is 4 hours all year – PST is behind AST.
AST and PST during daylight saving time
- AST next changes on 14 Mar 2027: clocks go forward one hour at 01:59 local time, from AST (UTC−4) to ADT (UTC−3).
- PST next changes on 14 Mar 2027: clocks go forward one hour at 01:59 local time, from PST (UTC−8) to PDT (UTC−7).
Best time for a meeting between AST and PST
AST and PST share 4 hours of the 9 AM–5 PM working day. Any time between 1:00 PM and 5:00 PM AST lands between 9:00 AM and 1:00 PM PST, inside working hours for both.
AST to PST FAQ
What is the time difference between AST and PST?
PST is 4 hours behind AST all year. 9:00 AM AST = 5:00 AM PST.
What is 9 AM AST in PST?
9:00 AM AST is 5:00 AM PST.
What is 12 PM (noon) AST in PST?
12:00 PM AST is 8:00 AM PST.
Is PST ahead of or behind AST?
PST is 4 hours behind AST, so it is earlier in PST than in AST.
Does AST change for daylight saving time?
Yes. AST next changes on 14 Mar 2027, when clocks go forward one hour from AST to ADT.
Does PST change for daylight saving time?
Yes. PST next changes on 14 Mar 2027, when clocks go forward one hour from PST to PDT.
What is the best time for a meeting between AST and PST?
AST and PST share 4 hours of the 9 AM–5 PM working day. Any time between 1:00 PM and 5:00 PM AST lands between 9:00 AM and 1:00 PM PST, inside working hours for both.
Is PT the same as PST?
PST is the winter (standard) name of Pacific Time (PT). From March to November the same clocks are called PDT. This converter always uses the one in force on the date you choose.
Related conversions
Convert PST to AST
Convert AST to other time zones
Convert other time zones to PST
Learn more
Updated 6 November 2026. Time zone data: IANA tz database.