Convert NZDT to AST

AST is 17 hours behind NZDT. NZDT is UTC+13 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 NZDT and AST. Someone has to take an early or late call — or use asynchronous communication instead.

NZDT to AST conversion table

About NZDT

New Zealand Daylight Time (NZDT) is UTC+13. It is used in New Zealand from late September to early April.

New Zealand Daylight Time is UTC+13, one of the few offsets past twelve hours and therefore a full calendar day ahead of most of the Americas. New Zealand's summer is the northern hemisphere's winter, so NZDT applies over Christmas — the opposite of every northern daylight-saving abbreviation, and a common mistake in end-of-year scheduling.

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 NZDT nor AST shifts with the seasons, so this 17-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 NZDT conversions

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

All time zone converters · Unix timestamp converter