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DateAlmanac

What is HST in AST?

Atlantic Time is 6 hours ahead

Hawaii Standard Time is on UTC−10:00 and Atlantic Time is on UTC−4:00 right now. The gap changes during the year — see below.

Convert a time

AST — Atlantic Time

4:00 am

AST, Sat, the next day

Time in Honolulu
10:29:27 PM
Time in Halifax
4:29:27 AM
Difference
+6 h
Next clock change
March 14, 2027

When the difference changes

Hawaii Standard Time and Atlantic Time do not change their clocks on the same dates, so the gap between them is not the same all year. Most converters show only today’s figure. These are the periods ahead:

  1. Now – March 13, 2027Atlantic Time is 6 hours ahead
  2. March 13, 2027 – November 6, 2027Atlantic Time is 7 hours ahead
  3. November 6, 2027 – onwardsAtlantic Time is 6 hours ahead

Periods shorter than a day are not listed. Each zone changes at its own local time, so on a date when both move there are a few hours when the gap is briefly something else.

Daylight saving

Hawaii Standard Time

No clock changes

Hawaii Standard Time stays on HST all year, so its offset from UTC never moves.

Atlantic Time

Sunday, March 14, 2027

Clocks go forward one hour — 2:00 am becomes 3:00 am local time, and the zone is on ADT after that.

HST to AST conversion table

Every hour of Friday, November 6, 2026, converted from Hawaii Standard Time to Atlantic Time. 6 of the 24 hours fall on a different calendar day in Halifax, which is marked.

12:00 am HST
6:00 am AST
1:00 am HST
7:00 am AST
2:00 am HST
8:00 am AST
3:00 am HST
9:00 am AST
4:00 am HST
10:00 am AST
5:00 am HST
11:00 am AST
6:00 am HST
12:00 pm AST
7:00 am HST
1:00 pm AST
8:00 am HST
2:00 pm AST
9:00 am HST
3:00 pm AST
10:00 am HST
4:00 pm AST
11:00 am HST
5:00 pm AST
12:00 pm HST
6:00 pm AST
1:00 pm HST
7:00 pm AST
2:00 pm HST
8:00 pm AST
3:00 pm HST
9:00 pm AST
4:00 pm HST
10:00 pm AST
5:00 pm HST
11:00 pm AST
6:00 pm HST
12:00 am AST+1 day
7:00 pm HST
1:00 am AST+1 day
8:00 pm HST
2:00 am AST+1 day
9:00 pm HST
3:00 am AST+1 day
10:00 pm HST
4:00 am AST+1 day
11:00 pm HST
5:00 am AST+1 day

Scheduling between the two

Working hours overlap from 9:00 am to 12:00 pm HST, which is 3:00 pm to 6:00 pm AST. Anything inside that window falls in the normal working day at both ends.

A note on AST: it can also mean Arabia Standard Time (UTC+3). This page means Atlantic Time.

Hawaii Standard Time (HST) is used in all of Hawaii, which does not observe daylight saving

Atlantic Time (AST) is used in Nova Scotia, New Brunswick and Puerto Rico

Other conversions