ACST to EDT
-13h 30mACST
ACSTSOURCEEDT
EDTGreen rows indicate typical business hours (9 AM - 5 PM)
ACST and EDT on the World Map
The map below highlights the ACST (Australian Central Standard Time) and EDT (Eastern Daylight Time) timezone regions across the globe.
ACST – Australian Central Standard Time
UTC+09:30Australian Central Standard Time (ACST, UTC+09:30) covers South Australia and the Northern Territory, on a half-hour offset.
- •ACST uses a half-hour offset: UTC+09:30.
- •South Australia moves to ACDT (UTC+10:30) in summer; the Northern Territory does not.
- •Adelaide and Darwin are 30 minutes apart during daylight saving, level in winter.
- •Adelaide is one of the few major cities on a 30-minute offset.
EDT – Eastern Daylight Time
UTC-04:00Eastern Daylight Time (EDT) is the daylight saving time observed in the Eastern Time Zone, 4 hours behind UTC.
- •EDT is observed from the second Sunday of March to the first Sunday of November.
- •During EDT, the US East Coast is only 4 hours behind London (instead of 5).
- •Not all EST locations switch to EDT – Panama and Jamaica stay on EST year-round.
ACST vs EDT: Offsets, DST and Best Call Times
ACST runs on Australian Central Standard Time (ACST) at UTC+09:30. EDT runs on Eastern Daylight Time (EDT) at UTC-04:00. That puts ACST 13 hours 30 minutes behind EDT — a difference of -13h 30m at the current offsets.
In practice, when it is 9:00 AM in ACST it is 7:30 PM in EDT on the previous day. Midnight in ACST is 10:30 AM in EDT. Neither zone observes daylight saving time, so the offset between them stays constant all year.
ACST to EDT time conversion table
| ACST (ACST) | EDT (EDT) | Day |
|---|---|---|
| 12:00 AM | 10:30 AM | previous day |
| 6:00 AM | 4:30 PM | previous day |
| 7:00 AM | 5:30 PM | previous day |
| 8:00 AM | 6:30 PM | previous day |
| 9:00 AM | 7:30 PM | previous day |
| 12:00 PM | 10:30 PM | previous day |
| 3:00 PM | 1:30 AM | same day |
| 5:00 PM | 3:30 AM | same day |
| 6:00 PM | 4:30 AM | same day |
| 9:00 PM | 7:30 AM | same day |
Why people convert ACST to EDT time
- Scheduling a call from ACST to EDT: a 10:00 AM start in ACST lands at 8:30 PM in EDT the previous day, so you can confirm the slot without doing the arithmetic yourself.
- Handling a -13h 30m gap: ACST and EDT have no overlap inside a normal 9-to-5 day, so real-time meetings need an early-morning or late-evening slot on one side. 9:00 AM in EDT is 7:30 PM in ACST.
- Booking travel or deliveries: tracking EDT local time against ACST keeps pickup windows and arrival estimates honest across the -13h 30m offset.
- Always state the zone abbreviation, not just the hour. "3:00 PM ACST" is unambiguous; "3 PM" across a -13h 30m gap is not.
- With a -13h 30m gap there is no shared 9-to-5 window, so alternate the early start: one week ACST takes the early slot, the next week EDT does.
About ACST (Australian Central Standard Time)
Australian Central Standard Time (ACST) is the half-hour offset of UTC+09:30 used across South Australia and the Northern Territory, taking in Adelaide and Darwin. South Australia moves to Australian Central Daylight Time (ACDT, UTC+10:30) from the first Sunday in October to the first Sunday in April, but the Northern Territory does not observe daylight saving — so Adelaide and Darwin sit 30 minutes apart in summer and level with each other in winter. The half-hour offset means Adelaide is 30 minutes behind Sydney in winter and level with it during daylight saving, which regularly catches out travellers and meeting planners.
About EDT (Eastern Daylight Time)
Eastern Daylight Time (EDT) is used during the summer months (second Sunday of March to the first Sunday of November) in the Eastern Time Zone. During EDT, clocks are advanced by one hour to take advantage of longer daylight hours. Not all locations in the Eastern Time Zone observe DST – Panama, Jamaica, and most of the Caribbean remain on EST year-round.
Best time to call between ACST and EDT
With a -13h 30m offset there is no overlap inside a normal 9 AM – 5 PM day. EDT opens at 9:00 AM EDT, which is 7:30 PM in ACST, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
ACST and EDT have no shared working hours because of the -13h 30m gap. Teams need to alternate early starts or rely on asynchronous handovers.
ACST is 13 hours 30 minutes behind EDT (ACST UTC+09:30 → EDT UTC-04:00). There is no shared 9-to-5 window, so plan around an early or late slot. Remember to re-check around daylight-saving transitions.
🕐 Daylight Saving Time Info
ACST
❄ Currently in Standard Time
Standard: UTC+09:30 · DST: UTC+10:30
Clocks spring forward on Sat, Oct 3, 2026
EDT
☀ Currently in DST
Standard: UTC-05:00 · DST: UTC-04:00
Clocks fall back on Sun, Nov 1, 2026
⚠ These locations are currently in different DST states, so the time difference may change when clocks adjust.
Learn More About Time
Dive deeper into the fascinating world of timekeeping, time zones, and how they shape our global society:
Frequently Asked Questions
What is the time difference between ACST and EDT?
ACST (ACST, UTC+09:30) is 13 hours 30 minutes behind EDT (EDT, UTC-04:00). The gap is currently -13h 30m.
How do I convert ACST time to EDT time?
Add -13h 30m to ACST local time. For example, 9:00 AM in ACST is 7:30 PM in EDT (previous day).
What time is it in EDT right now?
EDT uses EDT at UTC-04:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -13h 30m offset from ACST.
What is the best time to call EDT from ACST?
There is no shared working-hours window because of the -13h 30m gap. The closest option is 1:00 PM in ACST, which is 11:30 PM in EDT.
Which is behind, ACST or EDT?
ACST is 13 hours 30 minutes behind EDT. When it is 12:00 PM in ACST it is 10:30 PM in EDT.
Does daylight saving time affect the ACST–EDT difference?
Neither zone observes daylight saving time, so the -13h 30m offset between ACST and EDT is fixed all year.
Which other cities share ACST's time zone?
ACST also covers Adelaide, Darwin, Alice Springs, Mount Gambier.
Which countries use ACST, ACST's zone?
ACST is used in Australia (South Australia, Northern Territory).
Is there a day difference between ACST and EDT?
Sometimes. The -13h 30m gap is large enough that 8:00 PM or later in ACST already falls on the in EDT.
What is the time difference between ACST and EDT?
EDT is -13h 30m from ACST.
What timezone is ACST in?
ACST operates on its local timezone.
What timezone is EDT in?
EDT operates on its local timezone.
Which countries use ACST (Australian Central Standard Time)?
ACST is used in Australia (South Australia, Northern Territory).
Does ACST observe daylight saving time?
Yes, ACST switches to ACDT during summer months.
What are some interesting facts about ACST?
ACST uses a half-hour offset: UTC+09:30. South Australia moves to ACDT (UTC+10:30) in summer; the Northern Territory does not.
Which cities are in the EDT timezone?
Major cities in the EDT timezone include New York City, Washington D.C., Toronto, Miami, Philadelphia, Atlanta, Boston, Montreal.
What is the UTC offset for EDT?
Eastern Daylight Time (EDT) is at UTC-04:00. During daylight saving time, it shifts to EST.
What should I know about the EDT timezone?
EDT is observed from the second Sunday of March to the first Sunday of November. During EDT, the US East Coast is only 4 hours behind London (instead of 5).
When is it midnight in ACST, what time is it in EDT?
When it is 12:00 AM (midnight) in ACST (ACST), it is -13h 30m later in EDT (EDT).
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See every conversion from ACST →·See every conversion from EDT →