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.
IST
India Standard Time
GMT +5:30

Time Difference

Australian Central Standard Time is 4 hours ahead of India Standard Time
11:30 pm23:30 in ACST is 7:30 pm19:30 in IST

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

11:30 pm23:30 Australian Central Standard Time (ACST). Offset UTC +9:30 hours
7:30 pm19:30 India Standard Time (IST). Offset UTC +5:30 hours

11:30 pm23:30 ACST / 7:30 pm19:30 IST

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

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 3, 2021 at 2:00 am local time and clocks were set one hour forward to Sunday, October 3, 2021, 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 3, 2022 at 3:00 am local time and clocks are set one hour back to Sunday, April 3, 2022, 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

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