Convert HKT to AST

AST is 12 hours behind HKT. HKT is UTC+8 and AST is UTC−4.

Which AST is this?

AST names more than one zone. This page reads it as Atlantic Standard Time at UTC−4, which is the reading most converters take. There is one other: Arabia Standard Time at UTC+3, used in Saudi Arabia, Iraq, Kuwait, Bahrain, Qatar and Yemen.

The letters on a meeting invitation do not say which one is meant. If yours is not Atlantic Standard Time, the answer above is wrong, and not by a little:

The large converter sites disagree about this as well: search for a AST conversion and some of the results answer for one reading and some for another, none of them saying which they chose. Where it matters, ask which country the sender is in rather than which letters they typed.

Best time to schedule a meeting

Standard 9–5 working hours do not overlap at all between HKT and AST. Someone has to take an early or late call — or use asynchronous communication instead.

HKT to AST conversion table

About HKT

Hong Kong Time (HKT) is UTC+8. It is used in Hong Kong, and matching mainland China and Taiwan.

Hong Kong Time is UTC+8 and has had no daylight saving since 1979. It shares its offset with mainland China, Singapore, Taiwan, Manila and Perth, which makes UTC+8 the most economically dense single offset in the world — roughly a fifth of the planet's population runs on it, and a meeting scheduled in it reaches an unusual amount of Asia at once.

About AST

Atlantic Standard Time (AST) is UTC−4. It is used in Halifax, Puerto Rico and the eastern Caribbean in winter.

Atlantic Standard Time is UTC−4, one hour ahead of Eastern. It covers Canada's Atlantic provinces, Puerto Rico and much of the eastern Caribbean, and it is the reason a call from Halifax to Toronto is an hour out from what either party expects. The abbreviation is also used for Arabia Standard Time at UTC+3, seven hours away in the other direction, which is a genuinely dangerous collision in scheduling.

Does this gap change with the seasons?

Neither HKT nor AST shifts with the seasons, so this 12-hour difference holds all year. That is unusual enough to be worth relying on: most cross-continental gaps move twice a year.

This is the reason scheduling systems store an IANA zone such as Region/City rather than an offset or an abbreviation: the zone knows its own rules and the offset does not.

Frequently asked questions

Other HKT conversions

• HKT to UTC
• HKT to GMT
• HKT to EST
• HKT to EDT
• HKT to CST
• HKT to CDT
• HKT to MST
• HKT to MDT
• HKT to PST
• HKT to PDT
• HKT to AKST
• HKT to HST
• HKT to BRT
• HKT to BST
• HKT to CET
• HKT to CEST

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