IST
India Standard Time
GMT +5:30
ACST
Australian Central Standard Time
GMT +9:30
ACST is NOT in use by many locations
ACDT (Australian Central Daylight Time) is used instead. Switch to ACDT time zone or select one of the cities Adelaide, Darwin, Adelaide Hills) for automatic timezone change.

Time Difference

India Standard Time is 4 hours behind Australian Central Standard Time
1:30 am01:30 in IST is 5:30 am05:30 in ACST

IST to ACST call time
Best time for a conference call or a meeting is between 8am-2pm in IST which corresponds to 12pm-6pm in ACST

1:30 am01:30 India Standard Time (IST). Offset UTC +5:30 hours
5:30 am05:30 Australian Central Standard Time (ACST). Offset UTC +9:30 hours

1:30 am01:30 IST / 5:30 am05:30 ACST

IST ACST
12am (midnight) 4am
1am 5am
2am 6am
3am 7am
4am 8am
5am 9am
6am 10am
7am 11am
8am 12pm (noon)
9am 1pm
10am 2pm
11am 3pm
12pm (noon) 4pm
1pm 5pm
2pm 6pm
3pm 7pm
4pm 8pm
5pm 9pm
6pm 10pm
7pm 11pm
8pm 12am (midnight)
9pm 1am
10pm 2am
11pm 3am
0:00 4:00
1:00 5:00
2:00 6:00
3:00 7:00
4:00 8:00
5:00 9:00
6:00 10:00
7:00 11:00
8:00 12:00
9:00 13:00
10:00 14:00
11:00 15:00
12:00 16:00
13:00 17:00
14:00 18:00
15:00 19:00
16:00 20:00
17:00 21:00
18:00 22:00
19:00 23:00
20:00 0:00
21:00 1:00
22:00 2:00
23:00 3:00

India Standard Time

Offset: IST is 5 hours and 30 minutes ahead Greenwich Mean Time (GMT) and is used in Asia

Countries: It is used in following countries: India

Principal Cities: The largest city in the IST timezone is Mumbai from India with population about 12.692 million people. Other major cities in the area are Delhi, Bangalore, Kolkata, Chennai

Daylight Saving: India Standard Time (IST) is not adjusted for daylight saving therefore IST remains the same through out the year. This means, unlike some time zones where the clock is set forward by one hour every summer and backward by one hour during winter to adjust for daylight saving, India Standard Time remains the same

IST Time Zone Geo Map
IST timezone map

IST representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • +0530 - basic
  • +05:30 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0530 - sign character (+) followed by a four digit time providing hours (05) and minutes (30) of the offset. Indicates five hour and thirty minutes time differences to the east of the zero meridian.
IANA/Olson: Reflects IST time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • Asia/Calcutta
  • Asia/Kolkata
IST Abbreviation: Several time zones share IST abbreviation and it could refer to these time zones
  • India Standard Time - UTC +5:30
  • Irish Standard Time - UTC +1
  • Israel Standard Time - UTC +2
  • Iran Standard Time - UTC +3:30

Australian Central Standard Time

Offset: ACST is 9 hours and 30 minutes ahead Greenwich Mean Time (GMT) and is used in Australia

Countries: It is used in following countries: Australia

Principal Cities: The largest city in the ACST timezone is Adelaide from Australia with population about 1.225 million people. Other major cities in the area are Darwin, Adelaide Hills, Alice Springs, Palmerston

ACST Time Zone Geo Map
ACST timezone map

Daylight Saving: This is a standard time zone, however during summer some places switch clocks for one hour forward when daylight saving comes into effect and observe Australian Central Daylight Time (ACDT).

Daylight saving time clock moves forward for one hour from 2am to 3amEnd: Australian Central Standard Time (ACST) has ended on Sunday, October 2, 2022 at 2:00 am local time and clocks were set one hour forward to Sunday, October 2, 2022, 3:00 am local daylight time instead. Standard time ends annually the on first Sunday of October.

Daylight saving time clock moves back for one hour from 3am to 2amStart: Australian Central Standard Time (ACST) starts on Sunday, April 2, 2023 at 3:00 am local time and clocks are set one hour back to Sunday, April 2, 2023, 2:00 am. Standard time starts annually the on first Sunday of April.

ACST representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • +0930 - basic
  • +09:30 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0930 - sign character (+) followed by a four digit time providing hours (09) and minutes (30) of the offset. Indicates nine hour and thirty minutes time differences to the east of the zero meridian.
IANA/Olson: Reflects ACST time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • Australia/Adelaide
  • Australia/Broken_Hill
  • Australia/Darwin
  • Australia/North
  • Australia/South
  • Australia/Yancowinna