EST to AST
+1hEST
ESTSOURCEAST
ASTGreen rows indicate typical business hours (9 AM - 5 PM)
EST and AST on the World Map
The map below highlights the EST (Eastern Standard Time) and AST (Atlantic Standard Time) timezone regions across the globe.
EST – Eastern Standard Time
UTC-05:00Eastern Standard Time (EST) is the time zone for the eastern United States and Canada, 5 hours behind UTC.
- •EST is the most widely used time zone in the United States by population.
- •The New York Stock Exchange (NYSE) and NASDAQ operate on Eastern Time, opening at 9:30 AM EST.
- •23 US states are fully or partially in the Eastern Time Zone.
- •EST was established by the Standard Time Act of 1918.
- •Over 47% of the US population lives in the Eastern Time Zone.
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.
Understanding the +1h Gap: EST vs AST
EST runs on Eastern Standard Time (EST) at UTC-05:00. AST runs on Atlantic Standard Time (AST) at UTC-04:00. That puts EST 1 hour ahead of AST — a difference of +1h at the current offsets.
In practice, when it is 9:00 AM in EST it is 10:00 AM in AST. Midnight in EST is 1:00 AM in AST. Neither zone observes daylight saving time, so the offset between them stays constant all year.
EST to AST time conversion table
| EST (EST) | AST (AST) | Day |
|---|---|---|
| 12:00 AM | 1:00 AM | same day |
| 6:00 AM | 7:00 AM | same day |
| 7:00 AM | 8:00 AM | same day |
| 8:00 AM | 9:00 AM | same day |
| 9:00 AM | 10:00 AM | same day |
| 12:00 PM | 1:00 PM | same day |
| 3:00 PM | 4:00 PM | same day |
| 5:00 PM | 6:00 PM | same day |
| 6:00 PM | 7:00 PM | same day |
| 9:00 PM | 10:00 PM | same day |
Why people convert EST to AST time
- Scheduling a call from EST to AST: a 10:00 AM start in EST lands at 11:00 AM in AST, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both EST and AST are inside the 9-to-5 working day between 9:00 AM and 4:00 PM EST time (10:00 AM–5:00 PM AST). That is roughly 7 hours of usable overlap.
- Keeping family and friends in sync: knowing that 8:00 PM in EST is 9:00 PM in AST makes it easy to avoid calling at 3 AM.
- Always state the zone abbreviation, not just the hour. "3:00 PM EST" is unambiguous; "3 PM" across a +1h gap is not.
- Block 9:00 AM–4:00 PM EST as the recurring meeting window if you work primarily from EST and need AST colleagues present.
About EST (Eastern Standard Time)
Eastern Standard Time (EST) is observed during the winter months in the eastern part of North America. It covers 23 US states and parts of Canada including Ontario and Quebec. EST is the most populous time zone in the United States, home to major financial centers like New York City and global organizations headquartered in Washington D.C. During daylight saving time (March–November), clocks shift to Eastern Daylight Time (EDT, UTC-04:00). The time zone also covers parts of the Caribbean and Central America including Panama, Jamaica, and the Cayman Islands.
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.
Best time to call between EST and AST
Both EST and AST sit inside the 9 AM – 5 PM working day between 9:00 AM–4:00 PM EST, which is 10:00 AM–5:00 PM AST. That gives roughly 7 hours of shared time — the safest window for a live call or meeting.
Business hours overlap
EST and AST share 7 hours of working-hours overlap (9:00 AM–4:00 PM EST), so scheduling a live meeting is straightforward.
EST is 1 hour ahead of AST (EST UTC-05:00 → AST UTC-04:00). The shared working window is 9:00 AM–4:00 PM EST. Remember to re-check around daylight-saving transitions.
🕐 Daylight Saving Time Info
EST
☀ Currently in DST
Standard: UTC-05:00 · DST: UTC-04:00
Clocks fall back on Sun, Nov 1, 2026
AST
☀ Currently in DST
Standard: UTC-04:00 · DST: UTC-03:00
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 EST and AST?
EST (EST, UTC-05:00) is 1 hour ahead of AST (AST, UTC-04:00). The gap is currently +1h.
How do I convert EST time to AST time?
Add +1h to EST local time. For example, 9:00 AM in EST is 10:00 AM in AST.
What time is it in AST right now?
AST uses AST at UTC-04:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +1h offset from EST.
What is the best time to call AST from EST?
Call between 9:00 AM and 4:00 PM EST — that maps to 10:00 AM–5:00 PM AST and keeps both parties inside the working day.
Which is ahead, EST or AST?
EST is 1 hour ahead of AST. When it is 12:00 PM in EST it is 1:00 PM in AST.
Does daylight saving time affect the EST–AST difference?
Neither zone observes daylight saving time, so the +1h offset between EST and AST is fixed all year.
Which other cities share EST's time zone?
EST also covers New York City, Washington D.C., Miami, Toronto, Philadelphia, Atlanta, Boston, Montreal and 8 more.
Which countries use EST, EST's zone?
EST is used in United States (Eastern), Canada (Ontario, Quebec), Mexico (Quintana Roo), Panama, Jamaica, Cayman Islands, Haiti, Bahamas and 4 more.
Is there a day difference between EST and AST?
Not normally. The +1h gap only pushes the date over for late-evening times.
What is the time difference between EST and AST?
AST is +1h from EST.
What timezone is EST in?
EST operates on its local timezone.
What timezone is AST in?
AST operates on its local timezone.
Which countries use EST (Eastern Standard Time)?
EST is used in United States (Eastern), Canada (Ontario, Quebec), Mexico (Quintana Roo), Panama, Jamaica, Cayman Islands, and 6 more countries.
Does EST observe daylight saving time?
Yes, EST switches to EDT during summer months.
What are some interesting facts about EST?
EST is the most widely used time zone in the United States by population. The New York Stock Exchange (NYSE) and NASDAQ operate on Eastern Time, opening at 9:30 AM EST.
Which cities are in the AST timezone?
Major cities in the AST timezone include Halifax, San Juan, Santo Domingo, Caracas, La Paz, Fredericton, Charlottetown.
What is the UTC offset for AST?
Atlantic Standard Time (AST) is at UTC-04:00. During daylight saving time, it shifts to ADT.
What should I know about the AST timezone?
Puerto Rico uses AST year-round and does not observe DST. AST is 1 hour ahead of EST.
When is it midnight in EST, what time is it in AST?
When it is 12:00 AM (midnight) in EST (EST), it is +1h later in AST (AST).
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See every conversion from EST →·See every conversion from AST →