--:--:--
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San Juan · Barbados · Halifax (winter)
Need overlap across regions? Open the time zone meeting planner.
Difference
GMT vs AST
UTC → UTC
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London · Reykjavik · Accra
AST to GMT converter
Convert AST to GMT time now
Free AST to GMT converter. See Atlantic Standard Time and Greenwich Mean Time side by side. Live clocks, a 4 hours gap, meeting hours, and a full-day chart for San Juan and London.
America/Puerto_Rico
—
AST → GMT
To · Greenwich Mean Time
—
Etc/UTC
Interactive diagram
Watch AST convert into GMT
Drag the Atlantic hour. Watch the GMT clock change.
Atlantic
9:00 AM AST
—
GMT ← AST
GMT
—
Full-day chart
AST to GMT hourly conversion chart
Full-day table. Tap a row to copy. Labels follow daylight saving.
| Atlantic | GMT | UTC offsets |
|---|
Meeting times
Best AST to GMT meeting window
Find hours that work on both sides. Then save the slot to your calendar.
Follow along
Step-by-step AST to GMT conversion
Four short steps to convert any AST time to GMT.
Choose AST time
Select any hour in Atlantic Standard Time. Smart mode uses America/Puerto_Rico.
AST to GMT conversion guide
AST to GMT conversion guide
This AST to GMT converter shows Greenwich Mean Time (UTC±0) for any Atlantic Standard Time (UTC−4) time. Use it to schedule between San Juan and London. Choose Smart DST for live city clocks. Choose Fixed mode when you only want the AST and GMT labels.
Atlantic
AST
UTC−4
San Juan · Barbados · Halifax (winter)
AST vs GMT—
GMT
GMT
UTC±0
London · Reykjavik · Accra
What is AST to GMT conversion?
AST to GMT conversion turns a AST clock into the matching GMT time. Use it for calls, travel, and teams in San Juan and London.
AST to GMT time difference
GMT is 4 hours ahead of AST. Add 4 hours to the AST time to get GMT. The live clocks at the top show the current AST to GMT gap.
AST vs GMT
AST is UTC−4. GMT is UTC±0. They are different names. If a region uses daylight saving, check the live labels.
AST to GMT now / current time
Need ast to gmt right now? Read the live clocks, or tap Use current time for an instant AST → GMT result.
AST to GMT time difference
Season / context — tap to explore
See how daylight saving can change this pair.
Atlantic—
—AST → GMT
GMT—
Quick answers
Atlantic
Atlantic Standard Time (AST)
UTC−4
Atlantic Standard Time (AST) is UTC−4. Smart DST uses the city clock America/Puerto_Rico so daylight saving stays correct for San Juan · Barbados · Halifax (winter).
- Cities: San Juan · Barbados · Halifax (winter)
- City clock: America/Puerto_Rico
- Fixed AST: UTC−4
- On this page it pairs with GMT (UTC±0)
GMT
Greenwich Mean Time (GMT)
UTC±0
Same as UTC+0 here. London often uses BST in summer.
- Cities: London · Reykjavik · Accra
- City clock: Etc/UTC
- Fixed GMT: UTC±0
- From AST: GMT is 4 hours ahead of AST
AST to GMT FAQ