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DateAlmanac

What is IST in AST?

Atlantic Time is 8 hours 30 minutes behind

India Standard Time is on UTC+5:30 and Atlantic Time is on UTC−3:00 right now. Atlantic Time is on daylight saving, so its clocks read ADT. The gap changes during the year — see below.

Time in New Delhi
5:33:43 PM
Time in Halifax
9:03:43 AM
Difference
−8:30 h
Next clock change
November 1, 2026

Convert a time

ADT — Atlantic Time

8:30 am

ADT, Fri

When the difference changes

India 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 – November 1, 2026Atlantic Time is 8 hours 30 minutes behind
  2. November 1, 2026 – March 14, 2027Atlantic Time is 9 hours 30 minutes behind
  3. March 14, 2027 – onwardsAtlantic Time is 8 hours 30 minutes behind

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

India Standard Time

No clock changes

India Standard Time stays on IST all year, so its offset from UTC never moves.

Atlantic Time

Sunday, November 1, 2026

Clocks go back one hour — 2:00 am becomes 1:00 am local time, and the zone is on AST after that.

IST to AST conversion table

Every hour of Friday, September 25, 2026, converted from India Standard Time to Atlantic Time. 9 of the 24 hours fall on a different calendar day in Halifax, which is marked.

12:00 am IST
3:30 pm ADT−1 day
1:00 am IST
4:30 pm ADT−1 day
2:00 am IST
5:30 pm ADT−1 day
3:00 am IST
6:30 pm ADT−1 day
4:00 am IST
7:30 pm ADT−1 day
5:00 am IST
8:30 pm ADT−1 day
6:00 am IST
9:30 pm ADT−1 day
7:00 am IST
10:30 pm ADT−1 day
8:00 am IST
11:30 pm ADT−1 day
9:00 am IST
12:30 am ADT
10:00 am IST
1:30 am ADT
11:00 am IST
2:30 am ADT
12:00 pm IST
3:30 am ADT
1:00 pm IST
4:30 am ADT
2:00 pm IST
5:30 am ADT
3:00 pm IST
6:30 am ADT
4:00 pm IST
7:30 am ADT
5:00 pm IST
8:30 am ADT
6:00 pm IST
9:30 am ADT
7:00 pm IST
10:30 am ADT
8:00 pm IST
11:30 am ADT
9:00 pm IST
12:30 pm ADT
10:00 pm IST
1:30 pm ADT
11:00 pm IST
2:30 pm ADT

Scheduling between the two

There is no overlap between a nine-to-six working day in New Delhi and one in Halifax — the gap is too wide. A call has to sit early or late for one side. Early morning in New Delhi is the usual compromise, since that is late afternoon or evening in Halifax.

A note on IST: it can also mean Israel Standard Time (UTC+2) and Irish Standard Time (UTC+1). This page means India Standard Time, which is what almost all searches for IST want.

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

India Standard Time (IST) is used in all of India and Sri Lanka, on a single UTC+5:30 offset with no daylight saving

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

Other conversions