AST to GST Converter
Convert time between Atlantic Standard Time (AST) and Gulf Standard Time (GST)
Atlantic Standard Time (AST)
Gulf Standard Time (GST)
Time Difference
Gulf Standard Time (GST) is 0 hours ahead of Atlantic Standard Time (AST)
Select Date
Select Time
Quick Reference
| AST | GST |
|---|---|
| 23:00 | 06:00 |
| 01:00 | 08:00 |
| 03:00 | 10:00 |
| 05:00 | 12:00 |
| 07:00 | 14:00 |
| 09:00 | 16:00 |
| 11:00 | 18:00 |
| 13:00 | 20:00 |
| 15:00 | 22:00 |
| 17:00 | 00:00 |
| 19:00 | 02:00 |
| 21:00 | 04:00 |
Top 10 Most Common Time Zones
| Abbreviation | Full Name | UTC Offset | Typical Use |
|---|---|---|---|
| UTC | Coordinated Universal Time | UTC ±0 | Global reference standard (servers, logs, APIs) |
| EST / EDT | Eastern (US) Time | UTC −5 / −4 | New York, Toronto — North American business hub |
| CST / CDT | Central (US) Time | UTC −6 / −5 | Chicago, Dallas — US central business region |
| PST / PDT | Pacific (US) Time | UTC −8 / −7 | San Francisco, Los Angeles — tech industry standard |
| GMT / BST | Greenwich Mean / British Summer Time | UTC 0 / +1 | UK, used globally as a reference with UTC |
| CET / CEST | Central European (Summer) Time | UTC +1 / +2 | Paris, Berlin, Amsterdam — EU business core |
| IST | India Standard Time | UTC +5:30 | India — major IT & outsourcing region |
| CST | China Standard Time | UTC +8 | Beijing, Shanghai — East Asia business hub |
| JST | Japan Standard Time | UTC +9 | Tokyo — finance & tech hub |
| AEST / AEDT | Australian Eastern (Daylight) Time | UTC +10 / +11 | Sydney, Melbourne — APAC regional business |
Why Time Zone Abbreviations Are Ambiguous
Unlike standardized identifiers (like America/New_York or Europe/London from the IANA tz database), abbreviations such as "CST" or "IST" are not globally unique. They can refer to different time zones depending on context — country, region, or even time of year (due to daylight saving time).
Common Ambiguous Time Zone Abbreviations
| Abbrev. | Common Meaning(s) | UTC Offset | Region(s) |
|---|---|---|---|
| CST | Central Standard Time / China Standard Time / Cuba Standard Time | UTC−6 / UTC+8 / UTC−5 | North America, China, Cuba |
| IST | Indian Standard Time / Irish Standard Time / Israel Standard Time | UTC+5:30 / UTC+1 / UTC+2 | India, Ireland, Israel |
| AST | Atlantic Standard Time / Arabia Standard Time | UTC−4 / UTC+3 | Caribbean, Canada, Middle East |
| PST | Pacific Standard Time / Philippine Standard Time | UTC−8 / UTC+8 | North America, Philippines |
| EST | Eastern Standard Time (North America / Australia) | UTC−5 / UTC+10 | North America, Australia |
✅ Best Practice
To avoid ambiguity, always:
- Use IANA tz identifiers — e.g.,
America/New_Yorkinstead of "EST" - Specify UTC offset explicitly — e.g.,
UTC−5when abbreviations must be used - Include the full timezone name — e.g., "Eastern Standard Time (EST)" with UTC offset
About AST to GST Time Conversion
Converting time between Atlantic Standard Time (AST) and Gulf Standard Time (GST) involves an 8-hour difference. AST is UTC-4, while GST is UTC+4, making GST always 8 hours ahead of AST. This pairing connects Atlantic Canada with the UAE and Gulf region across opposite sides of the UTC line.
This time zone converter uses the IANA timezone database for accurate calculations. AST applies in Atlantic Canada during winter (November to March), while GST is observed year-round with no daylight saving. During Atlantic Canada's summer, the region moves to ADT (UTC-3), reducing the gap to 7 hours.
Common Use Cases for AST to GST Conversion
Business & Work
- Scheduling meetings between Halifax or Moncton offices and Dubai or Abu Dhabi teams
- Coordinating international trade and finance between Atlantic Canada and the Gulf
- Planning conference calls during the afternoon AST window that aligns with GST evening
Personal & Travel
- Planning travel itineraries between Atlantic Canada and the UAE
- Coordinating with family and friends in the Gulf region from Atlantic Canada
- Scheduling video calls that land within both parties' waking hours
Time Zone Information
Atlantic Standard Time (AST)
- UTC Offset: UTC-4 (UTC-3 during ADT)
- IANA Timezone: America/Halifax
- Daylight Saving: Second Sunday in March to First Sunday in November (ADT, UTC-3)
- Major Cities: Halifax, Moncton, Fredericton, Saint John, Charlottetown
- Coverage: New Brunswick, Nova Scotia, Prince Edward Island, and parts of Quebec (Canada)
Gulf Standard Time (GST)
- UTC Offset: UTC+4 (no daylight saving time)
- IANA Timezone: Asia/Dubai
- Daylight Saving: None — GST is observed year-round
- Major Cities: Dubai, Abu Dhabi, Sharjah, Muscat, Fujairah
- Coverage: United Arab Emirates and Oman
Quick Reference: AST to GST
Remember: GST is always 8 hours ahead of AST (7 hours ahead when Atlantic Canada is on ADT)
Frequently Asked Questions
What is the time difference between AST and GST?
Atlantic Standard Time (AST) is UTC-4, while Gulf Standard Time (GST) is UTC+4. GST is 8 hours ahead of AST. When it's 12:00 PM in Halifax (AST), it's 8:00 PM in Dubai (GST).
Does the time difference change throughout the year?
Yes. Atlantic Canada observes Atlantic Daylight Time (ADT, UTC-3) from March to November, reducing the gap to 7 hours ahead of GST. The UAE does not observe daylight saving time, so GST remains at UTC+4 year-round.
What are the best times for AST-GST business calls?
With GST 8 hours ahead, morning hours in Halifax align with the end of the Gulf business day. The best window is 9:00 AM–12:00 PM AST (5:00 PM–8:00 PM GST), catching Halifax in the morning and Dubai in the late afternoon.
Which countries use Gulf Standard Time (GST)?
GST (UTC+4) is used year-round by the United Arab Emirates and Oman. Major cities include Dubai, Abu Dhabi, Sharjah, and Muscat. GST never observes daylight saving time, making it a consistent reference point for scheduling.
Which regions use Atlantic Standard Time (AST)?
AST (UTC-4) is observed during winter months by Atlantic Canadian provinces including New Brunswick, Nova Scotia, Prince Edward Island, and parts of Quebec. Major cities include Halifax, Moncton, Fredericton, and Charlottetown.
How do I quickly convert AST to GST?
Add 8 hours to AST to get GST. For example, 10:00 AM AST becomes 6:00 PM GST. During Atlantic Canada's daylight saving time (ADT), add only 7 hours instead.
Pro Tips
- • GST is 8 hours ahead of AST — add 8 hours to convert Halifax time to Dubai time.
- • When Atlantic Canada switches to ADT (March–November), the gap drops to 7 hours.
- • Best meeting window: 9 AM–12 PM AST (5–8 PM GST) keeps Halifax in the morning and Dubai in the afternoon.
- • The UAE never observes DST, so GST stays fixed at UTC+4 all year — only the Atlantic Canada side shifts.
- • Atlantic Canada has growing tech and finance sectors with increasing ties to Gulf investors and markets.
- • For recurring calls, anchor the invite in GST since it never changes, and let the Atlantic Canada side adjust for ADT.