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HST to ACST Converter

Hawaii to central Australia — a 19.5-hour gap with seasonal variation due to daylight saving. Coordination typically centers on trade, investment, and remote team management.

Time Zone Converter

Compare Times

HSTACST
Morning
HSTACST
12:00 AM HST7:30 PM ACST
1:00 AM HST8:30 PM ACST
2:00 AM HST9:30 PM ACST
3:00 AM HST10:30 PM ACST
4:00 AM HST11:30 PM ACST
5:00 AM HST12:30 AM ACST
6:00 AM HST1:30 AM ACST
7:00 AM HST2:30 AM ACST
8:00 AM HST3:30 AM ACST
9:00 AM HST4:30 AM ACST
10:00 AM HST5:30 AM ACST
11:00 AM HST6:30 AM ACST
Afternoon
HSTACST
12:00 PM HST7:30 AM ACST
1:00 PM HST8:30 AM ACST
2:00 PM HST9:30 AM ACST
3:00 PM HST10:30 AM ACST
4:00 PM HST11:30 AM ACST
Evening
HSTACST
5:00 PM HST12:30 PM ACST
6:00 PM HST1:30 PM ACST
7:00 PM HST2:30 PM ACST
8:00 PM HST3:30 PM ACST
9:00 PM HST4:30 PM ACST
10:00 PM HST5:30 PM ACST
11:00 PM HST6:30 PM ACST

Common Time Conversions

How Time Zone Conversion Works

Time zone conversion works by comparing the UTC offset of one location to another. Every city or region is measured relative to Coordinated Universal Time (UTC), which acts as the global reference point for civil time.

ACST is 19 hours 30 minutes ahead of HST (standard time).

Daylight Saving Time: ACST observes DST; HST does not. The offset between them shifts by 1 hour twice a year — in spring and autumn — when ACST changes its clocks.

Best Meeting Times: HST & ACST

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Scheduling difficulty:Hard to overlap

HST

07:00–08:00

Hawaii Time

ACST

02:30–03:30

Central Australia Time

Recommended time: 07:00 HST / 02:30 ACST

tourismbusiness meetingsresources sectormilitary coordination

DST schedule for 2026

Current-year daylight saving start and end dates for the selected zones.

HST · Hawaii Time

Standard offset −10:00

Does not observe DST

Hawaii Time remains on a constant standard offset for the year.

Hawaii does not observe DST. The Aleutian Islands portion of HAST does observe DST (becoming HADT, UTC−9), but population there is negligible. For practical purposes HST is a fixed-offset zone.

ACST · Central Australia Time

Standard offset +09:30

Partial DST observance
Starts
Oct 4, 2026 · 02:00 → 03:00
first_sunday_of_october
Ends
Apr 5, 2026 · 03:00 → 02:00
first_sunday_of_april
Daylight time
ACDT · +10:30

South Australia observes DST (ACDT, UTC+10:30); the Northern Territory remains on ACST year-round. SA has used the same Sunday transition dates as the eastern states since the 2008/09 DST season — older sources stating SA changes one week later are out of date.

Principal Cities

HST — Hawaii Time

  • HonoluluUnited States
  • Pearl CityUnited States
  • HiloUnited States
  • KailuaUnited States

ACST — Central Australia Time

  • AdelaideAustralia
  • DarwinAustralia
  • Alice SpringsAustralia
  • PalmerstonAustralia

Convert from Hawaii Time

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Convert to Central Australia Time

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