HST to ACDT Converter
From Hawaii Standard Time to Australian Central Daylight Time: aCDT is 20 hours and 30 minutes ahead of HST. Use the editable converter to translate any HST time — including the date — into ACDT.
Daylight saving notes
In southern Australia, daylight saving time runs from the first Sunday in October to the first Sunday in April. That affects Australian Central Daylight Time (ACDT).
HST to ACDT conversion chart
For example, a 9:00 AM HST meeting takes place at 5:30 AM ACDT (+1 day). Concretely, when Honolulu (HST) and Adelaide (ACDT) set up a call, aCDT is 20 hours and 30 minutes ahead of HST.
| HST time | ACDT time |
|---|---|
| 12:00 AM | 8:30 PM |
| 1:00 AM | 9:30 PM |
| 2:00 AM | 10:30 PM |
| 3:00 AM | 11:30 PM |
| 4:00 AM | 12:30 AM+1 day |
| 5:00 AM | 1:30 AM+1 day |
| 6:00 AM | 2:30 AM+1 day |
| 7:00 AM | 3:30 AM+1 day |
| 8:00 AM | 4:30 AM+1 day |
| 9:00 AM | 5:30 AM+1 day |
| 10:00 AM | 6:30 AM+1 day |
| 11:00 AM | 7:30 AM+1 day |
| 12:00 PM | 8:30 AM+1 day |
| 1:00 PM | 9:30 AM+1 day |
| 2:00 PM | 10:30 AM+1 day |
| 3:00 PM | 11:30 AM+1 day |
| 4:00 PM | 12:30 PM+1 day |
| 5:00 PM | 1:30 PM+1 day |
| 6:00 PM | 2:30 PM+1 day |
| 7:00 PM | 3:30 PM+1 day |
| 8:00 PM | 4:30 PM+1 day |
| 9:00 PM | 5:30 PM+1 day |
| 10:00 PM | 6:30 PM+1 day |
| 11:00 PM | 7:30 PM+1 day |
This chart uses the fixed HST and ACDT offsets; the live converter above follows current daylight saving.
Convert HST to ACDT Time Zone
Everything you need for HST to ACDT — the difference, the current times, and how to plan around it.
How do I convert HST to ACDT?
It takes three quick steps:
- Click the HST field on the left and pick the time you want to convert.
- The matching ACDT time updates on the right automatically — there’s no button to press.
- Need a different day? Click the date field and the result follows, rolling over if it crosses midnight.
What is the time difference between HST and ACDT?
ACDT is 20 hours and 30 minutes ahead of HST. In everyday terms, once you know the time on one side you just add 20 hours 30 min to get the other — so a call between Honolulu and Adelaide is always 20 hours 30 min apart.
What time is it in ACDT right now?
Right now the time in Australian Central Daylight Time (ACDT) is Tuesday, June 30, 2026 · 4:23:57 AM. It ticks every second, so you’re always looking at the live ACDT clock.
What time is it in HST right now?
And in Hawaii Standard Time (HST), it’s currently Monday, June 29, 2026 · 7:53:57 AM. Compare the two and the 20 hours 30 min gap is easy to see.
What's the best time for a HST–ACDT call?
For example, a 9:00 AM HST meeting takes place at 5:30 AM ACDT (+1 day). The trick is to aim for a slot that lands inside normal working hours on both sides. Once you’ve found a time, hit Share on the converter to copy a link with the time built in — easy to send to a colleague. Juggling three or more zones? The meeting planner highlights the hours that overlap for everyone.
How does daylight saving affect HST to ACDT?
The labels HST and ACDT are fixed offsets, so the result on this page is always exact. One side switches between standard and summer time while the other stays put, so the real-world gap can shift by an hour for part of the year. It's worth checking which label a region is actually using before you lock in a time.
Why can you trust this HST to ACDT converter?
Every conversion here is calculated from the IANA time zone database — the same source your phone, computer, and browser rely on. Plenty of tools hard-code a single offset, which quietly goes wrong whenever a region changes its rules or flips for daylight saving. We follow the real rules instead, so HST to ACDT stays accurate for today and for any past or future date you type in.
Convert HST to other time zones
- UTC Coordinated Universal Time
- GMT Greenwich Mean Time
- EST Eastern Standard Time
- EDT Eastern Daylight Time
- CST Central Standard Time
- CDT Central Daylight Time
- MST Mountain Standard Time
- MDT Mountain Daylight Time
- PST Pacific Standard Time
- PDT Pacific Daylight Time
- AKST Alaska Standard Time
- AKDT Alaska Daylight Time
- AST Atlantic Standard Time
- ADT Atlantic Daylight Time
- NST Newfoundland Standard Time
- NDT Newfoundland Daylight Time
- BRT Brasília Time
- ART Argentina Time
- WET Western European Time
- WEST Western European Summer Time
- CET Central European Time
- CEST Central European Summer Time
- EET Eastern European Time
- EEST Eastern European Summer Time
- BST British Summer Time
- IST Irish Standard Time
- MSK Moscow Standard Time
- TRT Turkey Time
- WAT West Africa Time
- CAT Central Africa Time
- EAT East Africa Time
- SAST South Africa Standard Time
- GST Gulf Standard Time
- IST Israel Standard Time
- IDT Israel Daylight Time
- IST India Standard Time
- PKT Pakistan Standard Time
- BDT Bangladesh Standard Time
- ICT Indochina Time
- WIB Western Indonesian Time
- WITA Central Indonesian Time
- WIT Eastern Indonesian Time
- CST China Standard Time
- HKT Hong Kong Time
- SGT Singapore Time
- PHT Philippine Time
- JST Japan Standard Time
- KST Korea Standard Time
- AWST Australian Western Standard Time
- ACST Australian Central Standard Time
- ACDT Australian Central Daylight Time
- AEST Australian Eastern Standard Time
- AEDT Australian Eastern Daylight Time
- NZST New Zealand Standard Time
- NZDT New Zealand Daylight Time
Convert to ACDT from other time zones
- UTC Coordinated Universal Time
- GMT Greenwich Mean Time
- EST Eastern Standard Time
- EDT Eastern Daylight Time
- CST Central Standard Time
- CDT Central Daylight Time
- MST Mountain Standard Time
- MDT Mountain Daylight Time
- PST Pacific Standard Time
- PDT Pacific Daylight Time
- AKST Alaska Standard Time
- AKDT Alaska Daylight Time
- HST Hawaii Standard Time
- AST Atlantic Standard Time
- ADT Atlantic Daylight Time
- NST Newfoundland Standard Time
- NDT Newfoundland Daylight Time
- BRT Brasília Time
- ART Argentina Time
- WET Western European Time
- WEST Western European Summer Time
- CET Central European Time
- CEST Central European Summer Time
- EET Eastern European Time
- EEST Eastern European Summer Time
- BST British Summer Time
- IST Irish Standard Time
- MSK Moscow Standard Time
- TRT Turkey Time
- WAT West Africa Time
- CAT Central Africa Time
- EAT East Africa Time
- SAST South Africa Standard Time
- GST Gulf Standard Time
- IST Israel Standard Time
- IDT Israel Daylight Time
- IST India Standard Time
- PKT Pakistan Standard Time
- BDT Bangladesh Standard Time
- ICT Indochina Time
- WIB Western Indonesian Time
- WITA Central Indonesian Time
- WIT Eastern Indonesian Time
- CST China Standard Time
- HKT Hong Kong Time
- SGT Singapore Time
- PHT Philippine Time
- JST Japan Standard Time
- KST Korea Standard Time
- AWST Australian Western Standard Time
- ACST Australian Central Standard Time
- AEST Australian Eastern Standard Time
- AEDT Australian Eastern Daylight Time
- NZST New Zealand Standard Time
- NZDT New Zealand Daylight Time
Frequently asked questions
How many hours ahead of HST is ACDT?
ACDT is 20 hours and 30 minutes ahead of HST — a fixed 20 hours and 30 minutes difference, since both are fixed-offset labels.
What time is it in ACDT when it's 12:00 PM HST?
When it's 12:00 PM (noon) HST, it's 8:30 AM ACDT the next day.
Do HST or ACDT use daylight saving time?
Hawaii Standard Time (HST) is a fixed offset with no daylight saving; Australian Central Daylight Time (ACDT) observes daylight saving, alternating with ACST.
Why might the real-world HST–ACDT difference change during the year?
The labels HST and ACDT are fixed offsets, so this converter is always exact. But Australian Central Daylight Time's region switches between standard and summer time, so for part of the year you may actually want HST to ACST. Always check which label a region is currently using before you schedule.