AST to BST
+5hAST
ASTSOURCEBST
BSTGreen rows indicate typical business hours (9 AM - 5 PM)
AST and BST on the World Map
The map below highlights the AST (Atlantic Standard Time) and BST (British Summer 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.
BST – British Summer Time
UTC+01:00British Summer Time (BST, UTC+01:00) is the daylight saving period in the United Kingdom, running from late March to late October.
- •BST runs from the last Sunday in March to the last Sunday in October.
- •BST is exactly one hour ahead of GMT, the UK's standard time.
- •During BST, London is 4 hours ahead of New York while the US is on Eastern Daylight Time.
- •The Isle of Man and the Channel Islands also observe BST.
Comparing Time Zones: AST and BST
AST runs on Atlantic Standard Time (AST) at UTC-04:00. BST runs on British Summer Time (BST) at UTC+01:00. That puts AST 5 hours ahead of BST — a difference of +5h at the current offsets.
In practice, when it is 9:00 AM in AST it is 2:00 PM in BST. Midnight in AST is 5:00 AM in BST. Neither zone observes daylight saving time, so the offset between them stays constant all year.
AST to BST time conversion table
| AST (AST) | BST (BST) | Day |
|---|---|---|
| 12:00 AM | 5:00 AM | same day |
| 6:00 AM | 11:00 AM | same day |
| 7:00 AM | 12:00 PM | same day |
| 8:00 AM | 1:00 PM | same day |
| 9:00 AM | 2:00 PM | same day |
| 12:00 PM | 5:00 PM | same day |
| 3:00 PM | 8:00 PM | same day |
| 5:00 PM | 10:00 PM | same day |
| 6:00 PM | 11:00 PM | same day |
| 9:00 PM | 2:00 AM | next day |
Why people convert AST to BST time
- Scheduling a call from AST to BST: a 10:00 AM start in AST lands at 3:00 PM in BST, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both AST and BST are inside the 9-to-5 working day between 9:00 AM and 12:00 PM AST time (2:00 PM–5:00 PM BST). That is roughly 3 hours of usable overlap.
- Booking travel or deliveries: tracking BST local time against AST keeps pickup windows and arrival estimates honest across the +5h offset.
- Always state the zone abbreviation, not just the hour. "3:00 PM AST" is unambiguous; "3 PM" across a +5h gap is not.
- Block 9:00 AM–12:00 PM AST as the recurring meeting window if you work primarily from AST and need BST colleagues present.
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 BST (British Summer Time)
British Summer Time (BST) is the daylight saving period in the United Kingdom, when clocks move one hour forward from Greenwich Mean Time (GMT, UTC+00:00) to UTC+01:00. It runs from the last Sunday in March to the last Sunday in October. England, Scotland, Wales and Northern Ireland all follow it, along with the Isle of Man and the Channel Islands of Jersey and Guernsey. During BST, London is one hour ahead of UTC, four hours ahead of New York on Eastern Daylight Time, and five hours ahead of New York once the United States returns to Eastern Standard Time in November. BST is also used to abbreviate Bangladesh Standard Time (UTC+06:00), which is listed separately on this site.
Best time to call between AST and BST
Both AST and BST sit inside the 9 AM – 5 PM working day between 9:00 AM–12:00 PM AST, which is 2:00 PM–5:00 PM BST. That gives roughly 3 hours of shared time — the safest window for a live call or meeting.
Business hours overlap
AST and BST overlap for about 3 hours during the working day — enough for meetings if you avoid the edges of the window.
AST is 5 hours ahead of BST (AST UTC-04:00 → BST UTC+01:00). The shared working window is 9:00 AM–12:00 PM AST. Remember to re-check around daylight-saving transitions.
🕐 Daylight Saving Time Info
AST
☀ Currently in DST
Standard: UTC-04:00 · DST: UTC-03:00
Clocks fall back on Sun, Nov 1, 2026
BST
☀ Currently in DST
Standard: UTC+00:00 · DST: UTC+01:00
Clocks fall back on Sun, Oct 25, 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 BST?
AST (AST, UTC-04:00) is 5 hours ahead of BST (BST, UTC+01:00). The gap is currently +5h.
How do I convert AST time to BST time?
Add +5h to AST local time. For example, 9:00 AM in AST is 2:00 PM in BST.
What time is it in BST right now?
BST uses BST at UTC+01:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +5h offset from AST.
What is the best time to call BST from AST?
Call between 9:00 AM and 12:00 PM AST — that maps to 2:00 PM–5:00 PM BST and keeps both parties inside the working day.
Which is ahead, AST or BST?
AST is 5 hours ahead of BST. When it is 12:00 PM in AST it is 5:00 PM in BST.
Does daylight saving time affect the AST–BST difference?
Neither zone observes daylight saving time, so the +5h offset between AST and BST is fixed all year.
Which other cities share AST's time zone?
AST also covers Halifax, San Juan, Santo Domingo, Caracas, La Paz, Fredericton, Charlottetown.
Which countries use AST, AST's zone?
AST is used in Canada (Atlantic provinces), Puerto Rico, US Virgin Islands, Dominican Republic, Venezuela, Bolivia, Barbados, Trinidad and Tobago.
Is there a day difference between AST and BST?
Not normally. The +5h gap only pushes the date over for late-evening times.
What is the time difference between AST and BST?
BST is +5h from AST.
What timezone is AST in?
AST operates on its local timezone.
What timezone is BST in?
BST 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 BST timezone?
Major cities in the BST timezone include London, Birmingham, Manchester, Glasgow, Edinburgh, Cardiff, Belfast, Liverpool.
What is the UTC offset for BST?
British Summer Time (BST) is at UTC+01:00. During daylight saving time, it shifts to BST.
What should I know about the BST timezone?
BST runs from the last Sunday in March to the last Sunday in October. BST is exactly one hour ahead of GMT, the UK's standard time.
When is it midnight in AST, what time is it in BST?
When it is 12:00 AM (midnight) in AST (AST), it is +5h later in BST (BST).
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See every conversion from AST →·See every conversion from BST →