Thailand to AST
-11hThailand
ICTSOURCEAST
ASTGreen rows indicate typical business hours (9 AM - 5 PM)
ICT and AST on the World Map
The map below highlights the ICT (Indochina Time) and AST (Atlantic Standard Time) timezone regions across the globe.
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.
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.
Thailand to AST Time Difference – Complete Guide
Thailand runs on Indochina Time (ICT) at UTC+07:00. AST runs on Atlantic Standard Time (AST) at UTC-04:00. That puts Thailand 11 hours behind AST — a difference of -11h at the current offsets.
In practice, when it is 9:00 AM in Thailand it is 10:00 PM in AST on the previous day. Midnight in Thailand is 1:00 PM in AST. Neither zone observes daylight saving time, so the offset between them stays constant all year.
Thailand to AST time conversion table
| Thailand (ICT) | AST (AST) | Day |
|---|---|---|
| 12:00 AM | 1:00 PM | previous day |
| 6:00 AM | 7:00 PM | previous day |
| 7:00 AM | 8:00 PM | previous day |
| 8:00 AM | 9:00 PM | previous day |
| 9:00 AM | 10:00 PM | previous day |
| 12:00 PM | 1:00 AM | same day |
| 3:00 PM | 4:00 AM | same day |
| 5:00 PM | 6:00 AM | same day |
| 6:00 PM | 7:00 AM | same day |
| 9:00 PM | 10:00 AM | same day |
Why people convert Thailand to AST time
- Scheduling a call from Thailand to AST: a 10:00 AM start in Thailand lands at 11:00 PM in AST the previous day, so you can confirm the slot without doing the arithmetic yourself.
- Handling a -11h gap: Thailand and AST 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 AST is 10:00 PM in Thailand.
- Keeping family and friends in sync: knowing that 8:00 PM in Thailand is 9:00 AM in AST makes it easy to avoid calling at 3 AM.
- Always state the zone abbreviation, not just the hour. "3:00 PM ICT" 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 Thailand takes the early slot, the next week AST does.
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.
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.
Best time to call between Thailand and AST
With a -11h offset there is no overlap inside a normal 9 AM – 5 PM day. AST opens at 9:00 AM AST, which is 10:00 PM in Thailand, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
Thailand and AST have no shared working hours because of the -11h gap. Teams need to alternate early starts or rely on asynchronous handovers.
Thailand is 11 hours behind AST (ICT UTC+07:00 → AST 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
Thailand
Does not observe DST
AST
☀ Currently in DST
Standard: UTC-04:00 · DST: UTC-03:00
Clocks fall back on Sun, Nov 1, 2026
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 Thailand and AST?
Thailand (ICT, UTC+07:00) is 11 hours behind AST (AST, UTC-04:00). The gap is currently -11h.
How do I convert Thailand time to AST time?
Add -11h to Thailand local time. For example, 9:00 AM in Thailand is 10:00 PM in AST (previous day).
What time is it in AST right now?
AST uses AST at UTC-04:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -11h offset from Thailand.
What is the best time to call AST from Thailand?
There is no shared working-hours window because of the -11h gap. The closest option is 1:00 PM in Thailand, which is 2:00 AM in AST.
Which is behind, Thailand or AST?
Thailand is 11 hours behind AST. When it is 12:00 PM in Thailand it is 1:00 AM in AST.
Do Thailand and AST use different time zones?
Thailand (Thailand) uses ICT at UTC+07:00, while AST uses AST at UTC-04:00. The IANA identifiers are Asia/Bangkok and America/Halifax.
Does daylight saving time affect the Thailand–AST difference?
Neither zone observes daylight saving time, so the -11h offset between Thailand and AST is fixed all year.
Which other cities share Thailand's time zone?
ICT also covers Bangkok, Ho Chi Minh City, Hanoi, Jakarta, Phnom Penh, Vientiane.
Which countries use ICT, Thailand's zone?
ICT is used in Thailand, Vietnam, Cambodia, Laos, Indonesia (WIB).
Is there a day difference between Thailand and AST?
Not normally. The -11h gap only pushes the date over the previous day.
What is the time difference between Thailand and AST?
AST is -11h from Thailand.
What timezone is Thailand in?
Thailand operates on its local timezone.
What timezone is AST in?
AST operates on its local timezone.
Which countries use ICT (Indochina Time)?
ICT is used in Thailand, Vietnam, Cambodia, Laos, Indonesia (WIB).
Does ICT observe daylight saving time?
No, ICT does not observe daylight saving time and remains at UTC+07:00 year-round.
What are some interesting facts about ICT?
Bangkok is one of the most visited cities in the world. ICT is 12 hours ahead of EST.
Which cities are in the AST timezone?
Major cities in the AST timezone include Halifax, San Juan, Santo Domingo, Caracas, La Paz, Fredericton, Charlottetown.
What is the UTC offset for AST?
Atlantic Standard Time (AST) is at UTC-04:00. During daylight saving time, it shifts to ADT.
What should I know about the AST timezone?
Puerto Rico uses AST year-round and does not observe DST. AST is 1 hour ahead of EST.
When is it midnight in Thailand, what time is it in AST?
When it is 12:00 AM (midnight) in Thailand (ICT), it is -11h later in AST (AST).
Related Developer Tools
Explore more tools that work great with timezone conversions for international teams:
Related Timezone Conversions
More Thailand time conversions
- thailand to bangkok
- thailand to ict
- thailand to new york
- thailand to london
- thailand to dubai
- thailand to tokyo
- thailand to singapore
- thailand to sydney
- thailand to los angeles
- thailand to paris
- thailand to delhi
- thailand to mumbai
- thailand to berlin
- thailand to hong kong
- thailand to toronto
- thailand to kathmandu
- new york to thailand
- london to thailand
- dubai to thailand
- tokyo to thailand
- singapore to thailand
- sydney to thailand
- los angeles to thailand
- paris to thailand
- delhi to thailand
- mumbai to thailand
- berlin to thailand
- hong kong to thailand
- toronto to thailand
- kathmandu to thailand
See every conversion from Thailand →·See every conversion from AST →