IST to CHAST Time Converter

Convert India Standard Time (IST) to Chatham Standard Time (CHAST). Both time zones are shown live below; current offset between them is 7h 15m ahead.

Mumbai · India Standard Time
05:24:48
Wednesday, May 13, 2026
GMT+5:30 · UTC+05:30
Chatham Islands · Chatham Standard Time
12:39:48
Wednesday, May 13, 2026
GMT+12:45 · UTC+12:45

Convert a specific time

From: IST (Mumbai)
To: CHAST (Chatham Islands)
--:--

Daylight Saving status right now

IST (India Standard Time)
Observes DST
No
CHAST (Chatham Standard Time)
Observes DST
Yes
In DST right now
No
Next spring forward
2026-09-27
Offset shift
UTC+12:45 → UTC+13:45

Heads up: CHAST observes DST while IST does not. The 7.25-hour difference shown above will shift by one hour when CHAST starts or ends DST.

When can IST and CHAST meet?

00
01
02
03
04
05
06
07
08
09
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19
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IST
CHAST
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.
1 hour of overlap during standard 9am-5pm working hours.
Best meeting window: 09:00–09:00 IST (16:15–16:15 CHAST).

Hour-by-hour IST to CHAST conversion table

IST time (Mumbai)CHAST time (Chatham Islands)Status
00:00 Wed07:15 WedOff-hours both sides
01:00 Wed08:15 WedOff-hours both sides
02:00 Wed09:15 WedCHAST working
03:00 Wed10:15 WedCHAST working
04:00 Wed11:15 WedCHAST working
05:00 Wed12:15 WedCHAST working
06:00 Wed13:15 WedCHAST working
07:00 Wed14:15 WedCHAST working
08:00 Wed15:15 WedCHAST working
09:00 Wed16:15 WedBoth at work
10:00 Wed17:15 WedIST working
11:00 Wed18:15 WedIST working
12:00 Wed19:15 WedIST working
13:00 Wed20:15 WedIST working
14:00 Wed21:15 WedIST working
15:00 Wed22:15 WedIST working
16:00 Wed23:15 WedIST working
17:00 Wed00:15 ThuOff-hours both sides
18:00 Wed01:15 ThuOff-hours both sides
19:00 Wed02:15 ThuOff-hours both sides
20:00 Wed03:15 ThuOff-hours both sides
21:00 Wed04:15 ThuOff-hours both sides
22:00 Wed05:15 ThuOff-hours both sides
23:00 Wed06:15 ThuOff-hours both sides

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
Chatham Standard Time (CHAST)
IANA identifier
Pacific/Chatham
Current UTC offset
UTC+12:45
Current abbreviation
GMT+12:45
Major cities in this zone
Chatham Islands

Sun today in Mumbai and Chatham Islands

Mumbai
Sunrise
06:06
Sunset
19:06
Solar noon
12:36
Daylight
13h 0m

Related converters

CHAST to IST (reverse)IST to ESTIST to PSTIST to GMTIST to UTCIST to CETEST to CHASTPST to CHASTGMT to CHASTUTC to CHASTCET to CHAST
Looking for local time? See time in Mumbai or time in Chatham Islands.

Frequently asked questions

What is the time difference between IST and CHAST right now?+
CHAST (Chatham Standard Time) is currently 7h 15m ahead 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 CHAST observe daylight saving time?+
IST: does not observe daylight saving time. CHAST: observes daylight saving time.
When is the best time to schedule a meeting between IST and CHAST?+
The strongest overlap is 09:00–09:00 IST (16:15–16:15 CHAST), giving 1 hour when both sides are within standard 9am-5pm working hours.
What time is it in Chatham Islands when it is 12:00 noon in Mumbai?+
When it is 12:00 Wed in Mumbai (IST), it is 19:15 Wed in Chatham Islands (CHAST).
Which IANA time zone identifiers are used for IST and CHAST?+
IST maps to "Asia/Kolkata" in the IANA database. CHAST maps to "Pacific/Chatham". These identifiers are what most software libraries use to convert times accurately, including DST handling.
Is Mumbai ahead of or behind Chatham Islands?+
Whether Mumbai (IST) is ahead of or behind Chatham Islands (CHAST) depends on the current UTC offsets. Right now CHAST is 7h 15m ahead IST. The live converter and side-by-side clocks above always reflect the current direction.
What are the current UTC offsets for IST and CHAST?+
IST is UTC+05:30 (GMT+5:30) and CHAST is UTC+12:45 (GMT+12:45). 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 CHAST?+
Yes. There are 1 hour of overlap during standard 9am-5pm working hours, with the strongest window at 09:00–09:00 IST.