Convert Atlantic Standard Time to Pacific Standard Time (AST to PST)

Understanding AST and PST Time Zones

Atlantic Standard Time (AST)

Atlantic Standard Time is observed in undefined and uses the offset UTC-4. Major cities in this time zone include Halifax, San Juan. This time zone serves a significant global region with important economic and cultural hubs.

Pacific Standard Time (PST)

Pacific Standard Time operates at UTC-8, covering undefined. Key cities include Los Angeles, San Francisco, Seattle, Portland. The 4-hour backward offset from AST means that when professionals in Halifax start their workday at 9:00 AM, it is already 5:00 AM in Los Angeles.

AST is also commonly referred to as Atlantic Time, Puerto Rico time. PST is also known as Pacific Time, PT, West Coast time, LA time, California time. So if you are searching for Atlantic Time to Pacific Time, this is the same conversion as AST to PST.

Complete AST to PST Conversion Table

The table below shows every two-hour increment converted from Atlantic Standard Time to Pacific Standard Time. Business hours (9 AM – 5 PM) are highlighted for easy scheduling reference.

Times shown in 12-hour and 24-hour format. Last updated 2026-03-09.

Scheduling Between AST and PST

For business scheduling, the optimal overlap window between AST and PST falls roughly between 1:00 PM and 5:00 PM AST. This ensures both Halifax and Los Angeles teams are within standard working hours.

The moderate 4-hour gap between AST and PST means that there is a partial overlap of business hours. Teams can typically find a 3–4 hour window that works for both sides without requiring anyone to work outside normal hours.

Travel Between Halifax and Los Angeles

Travelers flying from Halifax to Los Angeles should adjust their sleep schedule 4 days before departure at a rate of one hour per day. For this time difference, gradual adjustment reduces jet lag dramatically.

Medical experts recommend allowing approximately one day of adjustment per hour of time difference. For the 4-hour shift between AST and PST, plan for about 4 days to fully acclimate.

Daylight Saving Time Considerations

During standard time months (November through March in the US), this offset is fixed. However, if either zone observes daylight saving time, the difference may temporarily shift by one hour during transition weeks in spring and autumn.

For the AST to PST conversion specifically: AST (UTC-4) does not observe DST, while PST (UTC-8) does observe DST. This means the offset between them changes by one hour seasonally — the usual 4-hour gap becomes 3 or 5 hours during DST transitions.

Related Time Zone Conversions

References & Resources

• TimeAndDate.com — World Time Zones
• NIST — Official US Time Standard
• IANA Time Zone Database
• Wikipedia — Time Zone Abbreviations
• WorldTimeServer — Current Times Worldwide

Frequently Asked Questions