AST to GST
+8hAST
ASTSOURCEGST
GSTGreen rows indicate typical business hours (9 AM - 5 PM)
AST and GST on the World Map
The map below highlights the AST (Atlantic Standard Time) and GST (Gulf Standard 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.
GST – Gulf Standard Time
UTC+04:00Gulf Standard Time (GST) is used in the UAE, Oman, and other Gulf states, 4 hours ahead of UTC.
- •Dubai uses GST year-round with no daylight saving time.
- •GST is 9 hours ahead of EST and 4 hours ahead of GMT.
- •The Dubai Financial Market (DFM) operates on GST.
Understanding the +8h Gap: AST vs GST
AST runs on Atlantic Standard Time (AST) at UTC-04:00. GST runs on Gulf Standard Time (GST) at UTC+04:00. That puts AST 8 hours ahead of GST — a difference of +8h at the current offsets.
In practice, when it is 9:00 AM in AST it is 5:00 PM in GST. Midnight in AST is 8:00 AM in GST. Neither zone observes daylight saving time, so the offset between them stays constant all year.
AST to GST time conversion table
| AST (AST) | GST (GST) | Day |
|---|---|---|
| 12:00 AM | 8:00 AM | same day |
| 6:00 AM | 2:00 PM | same day |
| 7:00 AM | 3:00 PM | same day |
| 8:00 AM | 4:00 PM | same day |
| 9:00 AM | 5:00 PM | same day |
| 12:00 PM | 8:00 PM | same day |
| 3:00 PM | 11:00 PM | same day |
| 5:00 PM | 1:00 AM | next day |
| 6:00 PM | 2:00 AM | next day |
| 9:00 PM | 5:00 AM | next day |
Why people convert AST to GST time
- Scheduling a call from AST to GST: a 10:00 AM start in AST lands at 6:00 PM in GST, so you can confirm the slot without doing the arithmetic yourself.
- Handling a +8h gap: AST and GST have no overlap inside a normal 9-to-5 day, so real-time meetings need an early-morning or late-evening slot on one side. 9:00 AM in GST is 5:00 PM in AST.
- Booking travel or deliveries: tracking GST local time against AST keeps pickup windows and arrival estimates honest across the +8h offset.
- Always state the zone abbreviation, not just the hour. "3:00 PM AST" is unambiguous; "3 PM" across a +8h gap is not.
- With a +8h gap there is no shared 9-to-5 window, so alternate the early start: one week AST takes the early slot, the next week GST does.
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 GST (Gulf Standard Time)
Gulf Standard Time (GST) is the time zone used in the United Arab Emirates, Oman, and other Gulf states. GST does not observe daylight saving time. Dubai and Abu Dhabi, major international business and tourism hubs, operate on GST.
Best time to call between AST and GST
With a +8h offset there is no overlap inside a normal 9 AM – 5 PM day. GST opens at 9:00 AM GST, which is 5:00 PM in AST, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
AST and GST have no shared working hours because of the +8h gap. Teams need to alternate early starts or rely on asynchronous handovers.
AST is 8 hours ahead of GST (AST UTC-04:00 → GST UTC+04:00). There is no shared 9-to-5 window, so plan around an early or late slot. 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
GST
Does not observe DST
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 GST?
AST (AST, UTC-04:00) is 8 hours ahead of GST (GST, UTC+04:00). The gap is currently +8h.
How do I convert AST time to GST time?
Add +8h to AST local time. For example, 9:00 AM in AST is 5:00 PM in GST.
What time is it in GST right now?
GST uses GST at UTC+04:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +8h offset from AST.
What is the best time to call GST from AST?
There is no shared working-hours window because of the +8h gap. The closest option is 1:00 PM in AST, which is 9:00 PM in GST.
Which is ahead, AST or GST?
AST is 8 hours ahead of GST. When it is 12:00 PM in AST it is 8:00 PM in GST.
Does daylight saving time affect the AST–GST difference?
Neither zone observes daylight saving time, so the +8h offset between AST and GST 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 GST?
Not normally. The +8h gap only pushes the date over for late-evening times.
What is the time difference between AST and GST?
GST is +8h from AST.
What timezone is AST in?
AST operates on its local timezone.
What timezone is GST in?
GST 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 GST timezone?
Major cities in the GST timezone include Dubai, Abu Dhabi, Muscat, Baku, Tbilisi.
What is the UTC offset for GST?
Gulf Standard Time (GST) is at UTC+04:00.
What should I know about the GST timezone?
Dubai uses GST year-round with no daylight saving time. GST is 9 hours ahead of EST and 4 hours ahead of GMT.
When is it midnight in AST, what time is it in GST?
When it is 12:00 AM (midnight) in AST (AST), it is +8h later in GST (GST).
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See every conversion from AST →·See every conversion from GST →