Convert JST to ACST

ACST is 30 minutes ahead of JST. JST is UTC+9 and ACST is UTC+9:30.

Best time to schedule a meeting

Standard 9–5 working hours overlap for 8 hours: 9:00 AM–5:00 PM JST (9:00 AM–5:00 PM ACST). Schedule meetings inside that window.

JST to ACST conversion table

About JST

Japan Standard Time (JST) is UTC+9. It is used in all of Japan, with no daylight saving.

Japan Standard Time is UTC+9 for the whole country and has had no daylight saving since 1951, when the occupation-era experiment was abandoned. Proposals to reintroduce it, most recently before the 2020 Olympics, have failed each time. The offset is shared with South Korea, so Tokyo and Seoul never differ by even a minute.

About ACST

Australian Central Standard Time (ACST) is UTC+9:30. It is used in Adelaide and Darwin in winter.

Australian Central Standard Time is UTC+9:30, half an hour behind the eastern states rather than a whole hour, which surprises people every time. South Australia moves to daylight saving in October and the Northern Territory does not, so Adelaide and Darwin share this offset for half the year and are an hour apart for the other half.

Does this gap change with the seasons?

Neither JST nor ACST shifts with the seasons, so this 0.5-hour difference holds all year. That is unusual enough to be worth relying on: most cross-continental gaps move twice a year.

This is the reason scheduling systems store an IANA zone such as Region/City rather than an offset or an abbreviation: the zone knows its own rules and the offset does not.

Frequently asked questions

Other JST conversions

• JST to UTC
• JST to GMT
• JST to EST
• JST to EDT
• JST to CST
• JST to CDT
• JST to MST
• JST to MDT
• JST to PST
• JST to PDT
• JST to AKST
• JST to HST
• JST to BRT
• JST to BST
• JST to CET
• JST to CEST

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