IST to AST Time Converter

Convert India Standard Time (IST) to Atlantic Standard Time (AST). Both time zones are shown live below; current offset between them is 8h 30m behind.

Mumbai · India Standard Time
18:38:24
Tuesday, May 12, 2026
GMT+5:30 · UTC+05:30
Halifax · Atlantic Standard Time
10:08:24
Tuesday, May 12, 2026
ADT · UTC-03:00

Convert a specific time

From: IST (Mumbai)
To: AST (Halifax)
--:--

Daylight Saving status right now

IST (India Standard Time)
Observes DST
No
AST (Atlantic Standard Time)
Observes DST
Yes
In DST right now
Yes
Next fall back
2026-11-01
Offset shift
UTC-03:00 → UTC-04:00

Heads up: AST observes DST while IST does not. The 8.5-hour difference shown above will shift by one hour when AST starts or ends DST.

When can IST and AST meet?

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01
02
03
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09
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IST
AST
Both zones in working hours (9am-5pm)
One zone working
Off-hours
Columns are hours of the day in Mumbai (IST). Each row shows the local working-hours state in that zone for the same moment in time.
No overlap during strict 9-5 working hours; some flexibility needed.
If both sides are willing to extend to 8am-7pm, the available window is 17:00–18:00 IST (08:30–09:30 AST).

Hour-by-hour IST to AST conversion table

IST time (Mumbai)AST time (Halifax)Status
00:00 Tue15:30 MonAST working
01:00 Tue16:30 MonAST working
02:00 Tue17:30 MonOff-hours both sides
03:00 Tue18:30 MonOff-hours both sides
04:00 Tue19:30 MonOff-hours both sides
05:00 Tue20:30 MonOff-hours both sides
06:00 Tue21:30 MonOff-hours both sides
07:00 Tue22:30 MonOff-hours both sides
08:00 Tue23:30 MonOff-hours both sides
09:00 Tue00:30 TueIST working
10:00 Tue01:30 TueIST working
11:00 Tue02:30 TueIST working
12:00 Tue03:30 TueIST working
13:00 Tue04:30 TueIST working
14:00 Tue05:30 TueIST working
15:00 Tue06:30 TueIST working
16:00 Tue07:30 TueIST working
17:00 Tue08:30 TueOff-hours both sides
18:00 Tue09:30 TueAST working
19:00 Tue10:30 TueAST working
20:00 Tue11:30 TueAST working
21:00 Tue12:30 TueAST working
22:00 Tue13:30 TueAST working
23:00 Tue14:30 TueAST working

Times computed for today in each zone using the IANA time zone database. The conversion accounts for daylight saving time wherever applicable.

About these time zones

India Standard Time (IST)
IANA identifier
Asia/Kolkata
Current UTC offset
UTC+05:30
Current abbreviation
GMT+5:30
Major cities in this zone
MumbaiNew DelhiBangaloreChennaiKolkata
Atlantic Standard Time (AST)
IANA identifier
America/Halifax
Current UTC offset
UTC-03:00
Current abbreviation
ADT
Major cities in this zone
Halifax

Sun today in Mumbai and Halifax

Mumbai
Sunrise
06:06
Sunset
19:05
Solar noon
12:36
Daylight
12h 59m

Related converters

AST to IST (reverse)IST to ESTIST to PSTIST to GMTIST to UTCIST to CETEST to ASTPST to ASTGMT to ASTUTC to ASTCET to AST
Looking for local time? See time in Mumbai or time in Halifax.

Frequently asked questions

What is the time difference between IST and AST right now?+
AST (Atlantic Standard Time) is currently 8h 30m behind IST (India Standard Time). The exact difference can change when one or both zones transition into or out of daylight saving time.
Does IST or AST observe daylight saving time?+
IST: does not observe daylight saving time. AST: observes daylight saving time.
When is the best time to schedule a meeting between IST and AST?+
Standard 9-5 hours do not overlap. Extending to 8am-7pm gives a window of 17:00–18:00 IST (08:30–09:30 AST).
What time is it in Halifax when it is 12:00 noon in Mumbai?+
When it is 12:00 Tue in Mumbai (IST), it is 03:30 Tue in Halifax (AST).
Which IANA time zone identifiers are used for IST and AST?+
IST maps to "Asia/Kolkata" in the IANA database. AST maps to "America/Halifax". These identifiers are what most software libraries use to convert times accurately, including DST handling.
Is Mumbai ahead of or behind Halifax?+
Whether Mumbai (IST) is ahead of or behind Halifax (AST) depends on the current UTC offsets. Right now AST is 8h 30m behind IST. The live converter and side-by-side clocks above always reflect the current direction.
What are the current UTC offsets for IST and AST?+
IST is UTC+05:30 (GMT+5:30) and AST is UTC-03:00 (ADT). Both offsets shift by one hour when the corresponding region enters or exits daylight saving time, so the live values on this page are the source of truth.
Can I schedule meetings during business hours for both IST and AST?+
Not during a strict 9am-5pm window. If both sides flex to 8am-7pm, the available meeting window between IST and AST is 17:00–18:00 IST.