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Beijing to AST

-12h

Beijing

CSTSOURCE
China · UTC+08:00
HH12
:
MM00
  
12:00 (24-hr)
12 AM6 AM12 PM6 PM12 AM

AST

AST
UTC-03:00☀ DST active
HH12
:
MM00
  
00:00 (24-hr)
12 AM6 AM12 PM6 PM12 AM
Beijing
AST
12:00 AM
1:00 PM-1
2:00 AM
3:00 PM-1
4:00 AM
5:00 PM-1
6:00 AM
7:00 PM-1
8:00 AM
9:00 PM-1
10:00 AM
11:00 PM-1
12:00 PM
1:00 AM
2:00 PM
3:00 AM
4:00 PM
5:00 AM
6:00 PM
7:00 AM
8:00 PM
9:00 AM
10:00 PM
11:00 AM

Green rows indicate typical business hours (9 AM - 5 PM)

CST and AST on the World Map

The map below highlights the CST (China Standard Time) and AST (Atlantic Standard Time) timezone regions across the globe.

CSTASTShanghaiBeijingShenzhenGuangzhouHalifaxSan JuanSanto DomingoCaracas
CST Zone
→
AST Zone

Explore all world timezones interactively →

CST – China Standard Time

UTC+08:00

China Standard Time (CST) covers all of mainland China, 8 hours ahead of UTC.

Countries in CST
ChinaHong KongMacauTaiwan
Major Cities in CST
ShanghaiBeijingShenzhenGuangzhouChengduHong KongTaipeiWuhanHangzhouNanjing
Key Facts about CST
  • •China uses a single time zone despite spanning 5 geographical zones.
  • •In Xinjiang (western China), sunset can be as late as midnight in summer.
  • •China abolished daylight saving time in 1991.
  • •The Shanghai Stock Exchange operates on CST/Beijing Time.
Daylight Saving:No – UTC+08:00 year-round
Learn more about CST on Wikipedia

AST – Atlantic Standard Time

UTC-04:00

Atlantic Standard Time (AST) is the time zone for the Canadian Atlantic provinces and the Caribbean, 4 hours behind UTC.

Countries in AST
Canada (Atlantic provinces)Puerto RicoUS Virgin IslandsDominican RepublicVenezuelaBoliviaBarbadosTrinidad and Tobago
Major Cities in AST
HalifaxSan JuanSanto DomingoCaracasLa PazFrederictonCharlottetown
Key Facts about AST
  • •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.
Daylight Saving:Yes – switches to ADT
Learn more about AST on Wikipedia

Time Conversion Guide: Beijing to AST

Beijing runs on China Standard Time (CST) at UTC+08:00. AST runs on Atlantic Standard Time (AST) at UTC-04:00. That puts Beijing 12 hours behind AST — a difference of -12h at the current offsets.

In practice, when it is 9:00 AM in Beijing it is 9:00 PM in AST on the previous day. Midnight in Beijing is 12:00 PM in AST. Neither zone observes daylight saving time, so the offset between them stays constant all year.

Beijing to AST time conversion table

Beijing (CST)AST (AST)Day
12:00 AM12:00 PMprevious day
6:00 AM6:00 PMprevious day
7:00 AM7:00 PMprevious day
8:00 AM8:00 PMprevious day
9:00 AM9:00 PMprevious day
12:00 PM12:00 AMsame day
3:00 PM3:00 AMsame day
5:00 PM5:00 AMsame day
6:00 PM6:00 AMsame day
9:00 PM9:00 AMsame day

Why people convert Beijing to AST time

  • Scheduling a call from Beijing to AST: a 10:00 AM start in Beijing 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: Beijing 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 Beijing.
  • Booking travel or deliveries: tracking AST local time against Beijing keeps pickup windows and arrival estimates honest across the -12h offset.
  • Always state the zone abbreviation, not just the hour. "3:00 PM CST" 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 Beijing takes the early slot, the next week AST does.

About CST (China Standard Time)

China Standard Time (CST, also known as Beijing Time) is used across all of mainland China despite the country spanning five geographical time zones. This single-timezone policy was adopted in 1949. China does not observe daylight saving time. CST is shared with Hong Kong (HKT), Macau, Taiwan, Singapore, Malaysia, and the Philippines, making UTC+08:00 one of the most used offsets in the world.

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 Beijing 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 Beijing, so real-time calls need an early-morning or late-evening slot on one side.

Business hours overlap

Beijing and AST have no shared working hours because of the -12h gap. Teams need to alternate early starts or rely on asynchronous handovers.

Beijing is 12 hours behind AST (CST 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

Beijing

Does not observe DST

AST

☀ Currently in DST

Standard: UTC-04:00 · DST: UTC-03:00

Clocks fall back on Sun, Nov 1, 2026

Frequently Asked Questions

What is the time difference between Beijing and AST?

Beijing (CST, UTC+08:00) is 12 hours behind AST (AST, UTC-04:00). The gap is currently -12h.

How do I convert Beijing time to AST time?

Add -12h to Beijing local time. For example, 9:00 AM in Beijing 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 Beijing.

What is the best time to call AST from Beijing?

There is no shared working-hours window because of the -12h gap. The closest option is 1:00 PM in Beijing, which is 1:00 AM in AST.

Which is behind, Beijing or AST?

Beijing is 12 hours behind AST. When it is 12:00 PM in Beijing it is 12:00 AM in AST.

Do Beijing and AST use different time zones?

Beijing (China) uses CST at UTC+08:00, while AST uses AST at UTC-04:00. The IANA identifiers are Asia/Shanghai and America/Halifax.

Does daylight saving time affect the Beijing–AST difference?

Neither zone observes daylight saving time, so the -12h offset between Beijing and AST is fixed all year.

Which other cities share Beijing's time zone?

CST also covers Shanghai, Beijing, Shenzhen, Guangzhou, Chengdu, Hong Kong, Taipei, Wuhan and 2 more.

Which countries use CST, Beijing's zone?

CST is used in China, Hong Kong, Macau, Taiwan.

Is there a day difference between Beijing and AST?

Sometimes. The -12h gap is large enough that 8:00 PM or later in Beijing already falls on the in AST.

What is the time difference between Beijing and AST?

AST is -12h from Beijing.

What timezone is Beijing in?

Beijing operates on its local timezone.

What timezone is AST in?

AST operates on its local timezone.

Which countries use CST (China Standard Time)?

CST is used in China, Hong Kong, Macau, Taiwan.

Does CST observe daylight saving time?

No, CST does not observe daylight saving time and remains at UTC+08:00 year-round.

What are some interesting facts about CST?

China uses a single time zone despite spanning 5 geographical zones. In Xinjiang (western China), sunset can be as late as midnight in summer.

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 Beijing, what time is it in AST?

When it is 12:00 AM (midnight) in Beijing (CST), it is -12h later in AST (AST).