HKT to AST
-12hHKT
HKTSOURCEAST
ASTGreen rows indicate typical business hours (9 AM - 5 PM)
HKT and AST on the World Map
The map below highlights the HKT (Hong Kong Time) and AST (Atlantic Standard Time) timezone regions across the globe.
HKT – Hong Kong Time
UTC+08:00Hong Kong Time (HKT, UTC+08:00) is the time zone for Hong Kong, 8 hours ahead of UTC.
- •Hong Kong does not observe daylight saving time and has kept UTC+08:00 since 1979.
- •HKT shares its offset with China Standard Time, Singapore Time and Philippine Time.
- •The Hong Kong Stock Exchange opens at 09:30 HKT.
- •Hong Kong Time does not change with the seasons, so its gap to other zones is fixed.
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.
HKT to AST Time Difference – Complete Guide
HKT runs on Hong Kong Time (HKT) at UTC+08:00. AST runs on Atlantic Standard Time (AST) at UTC-04:00. That puts HKT 12 hours behind AST — a difference of -12h at the current offsets.
In practice, when it is 9:00 AM in HKT it is 9:00 PM in AST on the previous day. Midnight in HKT is 12:00 PM in AST. Neither zone observes daylight saving time, so the offset between them stays constant all year.
HKT to AST time conversion table
| HKT (HKT) | AST (AST) | Day |
|---|---|---|
| 12:00 AM | 12:00 PM | previous day |
| 6:00 AM | 6:00 PM | previous day |
| 7:00 AM | 7:00 PM | previous day |
| 8:00 AM | 8:00 PM | previous day |
| 9:00 AM | 9:00 PM | previous day |
| 12:00 PM | 12:00 AM | same day |
| 3:00 PM | 3:00 AM | same day |
| 5:00 PM | 5:00 AM | same day |
| 6:00 PM | 6:00 AM | same day |
| 9:00 PM | 9:00 AM | same day |
Why people convert HKT to AST time
- Scheduling a call from HKT to AST: a 10:00 AM start in HKT lands at 10:00 PM in AST the previous day, so you can confirm the slot without doing the arithmetic yourself.
- Handling a -12h gap: HKT 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 9:00 PM in HKT.
- Watching a live event or market open: HKT viewers need 9:00 PM in AST to catch a 9:00 AM start there, and 12:00 PM if the event is anchored to HKT.
- Always state the zone abbreviation, not just the hour. "3:00 PM HKT" is unambiguous; "3 PM" across a -12h gap is not.
- With a -12h gap there is no shared 9-to-5 window, so alternate the early start: one week HKT takes the early slot, the next week AST does.
About HKT (Hong Kong Time)
Hong Kong Time (HKT) is fixed at UTC+08:00 all year and does not observe daylight saving time. Hong Kong last used summer time in 1979 and has kept a single offset since. HKT shares the UTC+08:00 offset with China Standard Time, Singapore Time, Malaysian Time, Philippine Time and Australian Western Standard Time, but is listed separately because Hong Kong maintains its own timekeeping authority. As a major financial centre, Hong Kong's trading hours set the rhythm for markets across Asia, opening at 09:30 HKT which is 01:30 in London and 20:30 the previous evening in New York.
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 HKT and AST
With a -12h offset there is no overlap inside a normal 9 AM – 5 PM day. AST opens at 9:00 AM AST, which is 9:00 PM in HKT, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
HKT and AST have no shared working hours because of the -12h gap. Teams need to alternate early starts or rely on asynchronous handovers.
HKT is 12 hours behind AST (HKT UTC+08:00 → 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
HKT
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 HKT and AST?
HKT (HKT, UTC+08:00) is 12 hours behind AST (AST, UTC-04:00). The gap is currently -12h.
How do I convert HKT time to AST time?
Add -12h to HKT local time. For example, 9:00 AM in HKT is 9:00 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 -12h offset from HKT.
What is the best time to call AST from HKT?
There is no shared working-hours window because of the -12h gap. The closest option is 1:00 PM in HKT, which is 1:00 AM in AST.
Which is behind, HKT or AST?
HKT is 12 hours behind AST. When it is 12:00 PM in HKT it is 12:00 AM in AST.
Does daylight saving time affect the HKT–AST difference?
Neither zone observes daylight saving time, so the -12h offset between HKT and AST is fixed all year.
Which other cities share HKT's time zone?
HKT also covers Hong Kong, Kowloon, Tsuen Wan, Sha Tin.
Which countries use HKT, HKT's zone?
HKT is used in Hong Kong SAR.
Is there a day difference between HKT and AST?
Sometimes. The -12h gap is large enough that 8:00 PM or later in HKT already falls on the in AST.
What is the time difference between HKT and AST?
AST is -12h from HKT.
What timezone is HKT in?
HKT operates on its local timezone.
What timezone is AST in?
AST operates on its local timezone.
Which countries use HKT (Hong Kong Time)?
HKT is used in Hong Kong SAR.
Does HKT observe daylight saving time?
No, HKT does not observe daylight saving time and remains at UTC+08:00 year-round.
What are some interesting facts about HKT?
Hong Kong does not observe daylight saving time and has kept UTC+08:00 since 1979. HKT shares its offset with China Standard Time, Singapore Time and Philippine Time.
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 HKT, what time is it in AST?
When it is 12:00 AM (midnight) in HKT (HKT), it is -12h later in AST (AST).
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See every conversion from HKT →·See every conversion from AST →