AST to Vietnam
+11hAST
ASTSOURCEVietnam
ICTGreen rows indicate typical business hours (9 AM - 5 PM)
AST and ICT on the World Map
The map below highlights the AST (Atlantic Standard Time) and ICT (Indochina 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.
ICT – Indochina Time
UTC+07:00Indochina Time (ICT) is the time zone for Vietnam, Thailand, Laos, and Cambodia, 7 hours ahead of UTC.
- •Bangkok is one of the most visited cities in the world.
- •ICT is 12 hours ahead of EST.
- •Thailand, Vietnam, and Cambodia all share ICT.
Understanding the +11h Gap: AST vs Vietnam
AST runs on Atlantic Standard Time (AST) at UTC-04:00. Vietnam runs on Indochina Time (ICT) at UTC+07:00. That puts AST 11 hours ahead of Vietnam — a difference of +11h at the current offsets.
In practice, when it is 9:00 AM in AST it is 8:00 PM in Vietnam. Midnight in AST is 11:00 AM in Vietnam. Neither zone observes daylight saving time, so the offset between them stays constant all year.
AST to Vietnam time conversion table
| AST (AST) | Vietnam (ICT) | Day |
|---|---|---|
| 12:00 AM | 11:00 AM | same day |
| 6:00 AM | 5:00 PM | same day |
| 7:00 AM | 6:00 PM | same day |
| 8:00 AM | 7:00 PM | same day |
| 9:00 AM | 8:00 PM | same day |
| 12:00 PM | 11:00 PM | same day |
| 3:00 PM | 2:00 AM | next day |
| 5:00 PM | 4:00 AM | next day |
| 6:00 PM | 5:00 AM | next day |
| 9:00 PM | 8:00 AM | next day |
Why people convert AST to Vietnam time
- Scheduling a call from AST to Vietnam: a 10:00 AM start in AST lands at 9:00 PM in Vietnam, so you can confirm the slot without doing the arithmetic yourself.
- Handling a +11h gap: AST and Vietnam 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 Vietnam is 8:00 PM in AST.
- Keeping family and friends in sync: knowing that 8:00 PM in AST is 7:00 AM in Vietnam makes it easy to avoid calling at 3 AM.
- Always state the zone abbreviation, not just the hour. "3:00 PM AST" is unambiguous; "3 PM" across a +11h gap is not.
- With a +11h gap there is no shared 9-to-5 window, so alternate the early start: one week AST takes the early slot, the next week Vietnam 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 ICT (Indochina Time)
Indochina Time (ICT) is used across Southeast Asia including Vietnam, Thailand, Laos, and Cambodia. Indonesia (Western time, WIB) also uses UTC+07:00. ICT does not observe daylight saving time.
Best time to call between AST and Vietnam
With a +11h offset there is no overlap inside a normal 9 AM – 5 PM day. Vietnam opens at 9:00 AM ICT, which is 8:00 PM in AST, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
AST and Vietnam have no shared working hours because of the +11h gap. Teams need to alternate early starts or rely on asynchronous handovers.
AST is 11 hours ahead of Vietnam (AST UTC-04:00 → ICT UTC+07:00). 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
Vietnam
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 Vietnam?
AST (AST, UTC-04:00) is 11 hours ahead of Vietnam (ICT, UTC+07:00). The gap is currently +11h.
How do I convert AST time to Vietnam time?
Add +11h to AST local time. For example, 9:00 AM in AST is 8:00 PM in Vietnam.
What time is it in Vietnam right now?
Vietnam uses ICT at UTC+07:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +11h offset from AST.
What is the best time to call Vietnam from AST?
There is no shared working-hours window because of the +11h gap. The closest option is 1:00 PM in AST, which is 12:00 AM in Vietnam.
Which is ahead, AST or Vietnam?
AST is 11 hours ahead of Vietnam. When it is 12:00 PM in AST it is 11:00 PM in Vietnam.
Do AST and Vietnam use different time zones?
AST uses AST at UTC-04:00, while Vietnam (Vietnam) uses ICT at UTC+07:00. The IANA identifiers are America/Halifax and Asia/Ho_Chi_Minh.
Does daylight saving time affect the AST–Vietnam difference?
Neither zone observes daylight saving time, so the +11h offset between AST and Vietnam 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 Vietnam?
Not normally. The +11h gap only pushes the date over for late-evening times.
What is the time difference between AST and Vietnam?
Vietnam is +11h from AST.
What timezone is AST in?
AST operates on its local timezone.
What timezone is Vietnam in?
Vietnam 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 ICT timezone?
Major cities in the ICT timezone include Bangkok, Ho Chi Minh City, Hanoi, Jakarta, Phnom Penh, Vientiane.
What is the UTC offset for ICT?
Indochina Time (ICT) is at UTC+07:00.
What should I know about the ICT timezone?
Bangkok is one of the most visited cities in the world. ICT is 12 hours ahead of EST.
When is it midnight in AST, what time is it in Vietnam?
When it is 12:00 AM (midnight) in AST (AST), it is +11h later in Vietnam (ICT).
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See every conversion from AST →·See every conversion from Vietnam →