JST
Japan Standard Time
GMT +9
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

Japan Standard Time is 0 hours and 30 minutes behind Australian Central Standard Time
3:00 pm15:00 in JST is 3:30 pm15:30 in ACST

JST to ACST call time
Best time for a conference call or a meeting is between 8am-5:30pm in JST which corresponds to 8:30am-6pm in ACST

3:00 pm15:00 Japan Standard Time (JST). Offset UTC +9:00 hours
3:30 pm15:30 Australian Central Standard Time (ACST). Offset UTC +9:30 hours

3:00 pm15:00 JST / 3:30 pm15:30 ACST

JST ACST
12am (midnight) 12:30 am
1am 1:30 am
2am 2:30 am
3am 3:30 am
4am 4:30 am
5am 5:30 am
6am 6:30 am
7am 7:30 am
8am 8:30 am
9am 9:30 am
10am 10:30 am
11am 11:30 am
12pm (noon) 12:30 pm
1pm 1:30 pm
2pm 2:30 pm
3pm 3:30 pm
4pm 4:30 pm
5pm 5:30 pm
6pm 6:30 pm
7pm 7:30 pm
8pm 8:30 pm
9pm 9:30 pm
10pm 10:30 pm
11pm 11:30 pm
0:00 0:30
1:00 1:30
2:00 2:30
3:00 3:30
4:00 4:30
5:00 5:30
6:00 6:30
7:00 7:30
8:00 8:30
9:00 9:30
10:00 10:30
11:00 11:30
12:00 12:30
13:00 13:30
14:00 14:30
15:00 15:30
16:00 16:30
17:00 17:30
18:00 18:30
19:00 19:30
20:00 20:30
21:00 21:30
22:00 22:30
23:00 23:30

Japan Standard Time

Offset: JST is 9 hours ahead Greenwich Mean Time (GMT) and is used in Asia

Countries: It is used in following countries: Japan

Principal Cities: The largest city in the JST timezone is Tokyo from Japan with population about 8.337 million people. Other major cities in the area are Yokohama, Osaka shi, Nagoya shi, Sapporo

Daylight Saving: Japan Standard Time (JST) is not adjusted for daylight saving therefore JST 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, Japan Standard Time remains the same

JST Time Zone Geo Map
JST timezone map

JST representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • +09 - basic short
  • +0900 - basic
  • +09:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0900 - sign character (+) followed by a four digit time providing hours (09) and minutes (00) of the offset. Indicates nine hour and zero minutes time differences to the east of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • India - Military abbreviation for JST
  • I - short form of 'India'
IANA/Olson: Reflects JST time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • Asia/Tokyo
  • Japan
Time zones with the GMT +9 offset:
  • AWDT - Australian Western Daylight Time
  • CHOST - Choibalsan Summer Time
  • I - India Time Zone
  • IRKST - Irkutsk Summer Time
  • JST - Japan Standard Time
  • KST - Korea Standard Time
  • PWT - Palau Time
  • TLT - East Timor Time
  • ULAST - Ulaanbaatar Summer Time
  • WIT - Eastern Indonesian Time
  • YAKT - Yakutsk Time

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