AST to PDT
-4hAST
ASTSOURCEPDT
PDTGreen rows indicate typical business hours (9 AM - 5 PM)
AST and PDT on the World Map
The map below highlights the AST (Atlantic Standard Time) and PDT (Pacific Daylight Time) timezone regions across the globe.
AST – Atlantic Standard Time
UTC-04:00Atlantic Standard Time (AST) is the time zone for the Canadian Atlantic provinces and the Caribbean, 4 hours behind UTC.
- •Puerto Rico uses AST year-round and does not observe DST.
- •AST is 1 hour ahead of EST.
- •Halifax, the capital of Nova Scotia, is the largest city in AST Canada.
PDT – Pacific Daylight Time
UTC-07:00Pacific Daylight Time (PDT) is the daylight saving offset on the US/Canada Pacific coast, 7 hours behind UTC.
- •PDT aligns with MST at UTC-07:00.
- •Tech company earnings calls often reference PDT/PST times.
Understanding the Time Gap: AST vs PDT
AST (Atlantic Standard Time) operates on the Atlantic Standard Time (UTC-04:00). PDT (Pacific Daylight Time) uses Pacific Daylight Time (UTC-07:00).
The time difference between AST and PDT is 240 minutes (+4h). When it's noon in AST, it's 08:00 AM in PDT.
Why Convert AST to PDT Time?
When planning a meeting or scheduling a call between AST and PDT, it's crucial to account for the 4-hour time difference. Whether you're coordinating with remote teams, calling family, or setting up an international conference, knowing the exact time in PDT helps avoid missed connections.
Tip: When scheduling a meeting, always confirm the time zone with your counterpart in PDT. The 4-hour difference can easily lead to confusion if not explicitly stated.
About AST (Atlantic Standard Time)
Atlantic Standard Time (AST) covers Canada's Atlantic provinces (Nova Scotia, New Brunswick, Prince Edward Island, and most of Labrador), as well as several Caribbean nations. Puerto Rico and the US Virgin Islands use AST year-round without daylight saving time. The Canadian provinces switch to Atlantic Daylight Time (ADT) in summer.
About PDT (Pacific Daylight Time)
Pacific Daylight Time (PDT) is observed from March to November on the Pacific coast. During PDT, the west coast is 7 hours behind UTC and only 2 hours behind the east coast's EDT.
Best Time to Call Between AST and PDT
If you want to reach someone in PDT during standard business hours (9 AM – 5 PM PDT), the best time to call from AST would be:
- PDT 9:00 AM = AST 01:00 PM
- PDT 12:00 PM = AST 04:00 PM
- PDT 5:00 PM = AST 09:00 PM
Business Hours Overlap
AST and PDT have a partial business hours overlap. The best window for meetings and calls is when both locations are in their working hours.
As a final note, managing the -4h difference between AST and PDT is simple with the right tools. Keep this page handy for all your future time conversion needs.
🕐 Daylight Saving Time Info
AST
☀ Currently in DST
Standard: UTC-04:00 · DST: UTC-03:00
Clocks fall back on Sun, Nov 1, 2026
PDT
☀ Currently in DST
Standard: UTC-08:00 · DST: UTC-07:00
Clocks fall back on Sun, Nov 1, 2026
Learn More About Time
Dive deeper into the fascinating world of timekeeping, time zones, and how they shape our global society:
Frequently Asked Questions
What is the time difference between AST and PDT?
PDT is -4h from AST.
What timezone is AST in?
AST operates on its local timezone.
What timezone is PDT in?
PDT operates on its local timezone.
Which countries use AST (Atlantic Standard Time)?
AST is used in Canada (Atlantic provinces), Puerto Rico, US Virgin Islands, Dominican Republic, Venezuela, Bolivia, and 2 more countries.
Does AST observe daylight saving time?
Yes, AST switches to ADT during summer months.
What are some interesting facts about AST?
Puerto Rico uses AST year-round and does not observe DST. AST is 1 hour ahead of EST.
Which cities are in the PDT timezone?
Major cities in the PDT timezone include Los Angeles, San Francisco, Seattle, Vancouver, Portland.
What is the UTC offset for PDT?
Pacific Daylight Time (PDT) is at UTC-07:00. During daylight saving time, it shifts to PST.
What should I know about the PDT timezone?
PDT aligns with MST at UTC-07:00. Tech company earnings calls often reference PDT/PST times.
When is it midnight in AST, what time is it in PDT?
When it is 12:00 AM (midnight) in AST (AST), it is -4h later in PDT (PDT).
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