GMT to AST Converter
AST is 4 hours behind GMT. 9:00 AM GMT = 5:00 AM AST.
AST is 4 hours behind GMT at the moment. To convert GMT to AST, subtract 4 hours from the GMT time: 9:00 AM GMT = 5:00 AM AST.
GMT (GMT) is used in Same offset as UTC. The UK and Ireland use GMT in winter; Iceland, Ghana and Senegal all year. AST (Atlantic Time) is used in Nova Scotia, New Brunswick, PEI; Puerto Rico and the Eastern Caribbean (all year).
The UK is on GMT only in winter; in summer it uses BST (UTC+1). AST here is Atlantic Standard Time, not Arabia Standard Time.
GMT to AST time conversion table
GMT to AST on 6 Nov 2026. Today's date. Highlighted rows are 9 AM–5 PM in both places.
| GMT | AST | Day |
|---|---|---|
| 12:00 AM GMT | 8:00 PM AST | previous day |
| 1:00 AM GMT | 9:00 PM AST | previous day |
| 2:00 AM GMT | 10:00 PM AST | previous day |
| 3:00 AM GMT | 11:00 PM AST | previous day |
| 4:00 AM GMT | 12:00 AM AST | night |
| 5:00 AM GMT | 1:00 AM AST | night |
| 6:00 AM GMT | 2:00 AM AST | night |
| 7:00 AM GMT | 3:00 AM AST | night |
| 8:00 AM GMT | 4:00 AM AST | night |
| 9:00 AM GMT | 5:00 AM AST | night |
| 10:00 AM GMT | 6:00 AM AST | — |
| 11:00 AM GMT | 7:00 AM AST | — |
| 12:00 PM GMT | 8:00 AM AST | — |
| 1:00 PM GMT | 9:00 AM AST | work hours |
| 2:00 PM GMT | 10:00 AM AST | work hours |
| 3:00 PM GMT | 11:00 AM AST | work hours |
| 4:00 PM GMT | 12:00 PM AST | work hours |
| 5:00 PM GMT | 1:00 PM AST | — |
| 6:00 PM GMT | 2:00 PM AST | — |
| 7:00 PM GMT | 3:00 PM AST | — |
| 8:00 PM GMT | 4:00 PM AST | — |
| 9:00 PM GMT | 5:00 PM AST | — |
| 10:00 PM GMT | 6:00 PM AST | — |
| 11:00 PM GMT | 7:00 PM AST | — |
- Work rows — 9 AM–5 PM in both places
- Night in the destination (10 PM–6 AM)
How to convert GMT to AST
Subtract 4 hours from the GMT time to get AST.
Example: 9:00 AM GMT = 5:00 AM AST.
Across midnight: 1:00 AM GMT = 9:00 PM AST (previous day). The date changes, so always check the day as well as the hour.
Time difference between GMT and AST
The time difference between GMT and AST is not the same all year, because the two sides change for daylight saving time on different dates. In 2026 it works out like this:
- 1 Jan 2026 – 7 Mar 2026: AST is 4 hours behind of GMT.
- 8 Mar 2026 – 31 Oct 2026: AST is 3 hours behind of GMT.
- 1 Nov 2026 – 31 Dec 2026: AST is 4 hours behind of GMT.
GMT and AST during daylight saving time
- GMT does not observe daylight saving time; it stays on UTC+0 all year.
- 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).
Best time for a meeting between GMT and AST
GMT and AST share 4 hours of the 9 AM–5 PM working day. Any time between 1:00 PM and 5:00 PM GMT lands between 9:00 AM and 1:00 PM AST, inside working hours for both.
GMT to AST FAQ
What is the time difference between GMT and AST?
Right now AST is 4 hours behind GMT. The gap changes 3 times in 2026 because the two sides switch to daylight saving time on different dates.
What is 9 AM GMT in AST?
9:00 AM GMT is 5:00 AM AST.
What is 12 PM (noon) GMT in AST?
12:00 PM GMT is 8:00 AM AST.
Is AST ahead of or behind GMT?
AST is 4 hours behind GMT, so it is earlier in AST than in GMT.
Does GMT change for daylight saving time?
No. GMT stays on the same offset all year, so conversions never shift for daylight saving time.
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.
What is the best time for a meeting between GMT and AST?
GMT and AST share 4 hours of the 9 AM–5 PM working day. Any time between 1:00 PM and 5:00 PM GMT lands between 9:00 AM and 1:00 PM AST, inside working hours for both.
Related conversions
Convert AST to GMT
Convert GMT to other time zones
Convert other time zones to AST
Learn more
Updated 6 November 2026. Time zone data: IANA tz database.