AEDT to AST
-15hAEDT
AEDTSOURCEAST
ASTGreen rows indicate typical business hours (9 AM - 5 PM)
AEDT and AST on the World Map
The map below highlights the AEDT (Australian Eastern Daylight Time) and AST (Atlantic Standard Time) timezone regions across the globe.
AEDT – Australian Eastern Daylight Time
UTC+11:00Australian Eastern Daylight Time (AEDT, UTC+11:00) is the daylight saving period in south-eastern Australia, from October to April.
- •AEDT runs from the first Sunday in October to the first Sunday in April.
- •AEDT is one hour ahead of Australian Eastern Standard Time (AEST).
- •Queensland does not observe daylight saving, so Brisbane stays on AEST.
- •During AEDT, Sydney is 16 hours ahead of New York and 11 hours ahead of UTC.
AST – Atlantic Standard Time
UTC-04:00Atlantic Standard Time (AST) is the time zone for the Canadian Atlantic provinces and the Caribbean, 4 hours behind UTC.
- •Puerto Rico uses AST year-round and does not observe DST.
- •AST is 1 hour ahead of EST.
- •Halifax, the capital of Nova Scotia, is the largest city in AST Canada.
AEDT vs AST: Offsets, DST and Best Call Times
AEDT runs on Australian Eastern Daylight Time (AEDT) at UTC+11:00. AST runs on Atlantic Standard Time (AST) at UTC-04:00. That puts AEDT 15 hours behind AST — a difference of -15h at the current offsets.
In practice, when it is 9:00 AM in AEDT it is 6:00 PM in AST on the previous day. Midnight in AEDT is 9:00 AM in AST. Neither zone observes daylight saving time, so the offset between them stays constant all year.
AEDT to AST time conversion table
| AEDT (AEDT) | AST (AST) | Day |
|---|---|---|
| 12:00 AM | 9:00 AM | previous day |
| 6:00 AM | 3:00 PM | previous day |
| 7:00 AM | 4:00 PM | previous day |
| 8:00 AM | 5:00 PM | previous day |
| 9:00 AM | 6:00 PM | previous day |
| 12:00 PM | 9:00 PM | previous day |
| 3:00 PM | 12:00 AM | same day |
| 5:00 PM | 2:00 AM | same day |
| 6:00 PM | 3:00 AM | same day |
| 9:00 PM | 6:00 AM | same day |
Why people convert AEDT to AST time
- Scheduling a call from AEDT to AST: a 10:00 AM start in AEDT lands at 7:00 PM in AST the previous day, so you can confirm the slot without doing the arithmetic yourself.
- Handling a -15h gap: AEDT and AST 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 AST is 6:00 PM in AEDT.
- Keeping family and friends in sync: knowing that 8:00 PM in AEDT is 5:00 AM in AST makes it easy to avoid calling at 3 AM.
- Always state the zone abbreviation, not just the hour. "3:00 PM AEDT" is unambiguous; "3 PM" across a -15h gap is not.
- With a -15h gap there is no shared 9-to-5 window, so alternate the early start: one week AEDT takes the early slot, the next week AST does.
About AEDT (Australian Eastern Daylight Time)
Australian Eastern Daylight Time (AEDT) is the daylight saving period in south-eastern Australia, one hour ahead of Australian Eastern Standard Time (AEST, UTC+10:00). Because Australia is in the southern hemisphere, AEDT runs through the summer — from the first Sunday in October to the first Sunday in April — which is almost exactly the reverse of the European and North American schedules. New South Wales, Victoria, Tasmania and the Australian Capital Territory observe it; Queensland and the Northern Territory do not, so Brisbane stays on AEST year round while Sydney moves to AEDT. During AEDT, Sydney is 11 hours ahead of UTC and 16 hours ahead of New York.
About AST (Atlantic Standard Time)
Atlantic Standard Time (AST) covers Canada's Atlantic provinces (Nova Scotia, New Brunswick, Prince Edward Island, and most of Labrador), as well as several Caribbean nations. Puerto Rico and the US Virgin Islands use AST year-round without daylight saving time. The Canadian provinces switch to Atlantic Daylight Time (ADT) in summer.
Best time to call between AEDT and AST
With a -15h offset there is no overlap inside a normal 9 AM – 5 PM day. AST opens at 9:00 AM AST, which is 6:00 PM in AEDT, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
AEDT and AST have no shared working hours because of the -15h gap. Teams need to alternate early starts or rely on asynchronous handovers.
AEDT is 15 hours behind AST (AEDT UTC+11:00 → AST 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
AEDT
❄ Currently in Standard Time
Standard: UTC+10:00 · DST: UTC+11:00
Clocks spring forward on Sat, Oct 3, 2026
AST
☀ Currently in DST
Standard: UTC-04:00 · DST: UTC-03:00
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 AEDT and AST?
AEDT (AEDT, UTC+11:00) is 15 hours behind AST (AST, UTC-04:00). The gap is currently -15h.
How do I convert AEDT time to AST time?
Add -15h to AEDT local time. For example, 9:00 AM in AEDT is 6:00 PM in AST (previous day).
What time is it in AST right now?
AST uses AST at UTC-04:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -15h offset from AEDT.
What is the best time to call AST from AEDT?
There is no shared working-hours window because of the -15h gap. The closest option is 1:00 PM in AEDT, which is 10:00 PM in AST.
Which is behind, AEDT or AST?
AEDT is 15 hours behind AST. When it is 12:00 PM in AEDT it is 9:00 PM in AST.
Does daylight saving time affect the AEDT–AST difference?
Neither zone observes daylight saving time, so the -15h offset between AEDT and AST is fixed all year.
Which other cities share AEDT's time zone?
AEDT also covers Sydney, Melbourne, Canberra, Hobart, Newcastle.
Which countries use AEDT, AEDT's zone?
AEDT is used in Australia (NSW, Victoria, Tasmania, ACT).
Is there a day difference between AEDT and AST?
Sometimes. The -15h gap is large enough that 8:00 PM or later in AEDT already falls on the in AST.
What is the time difference between AEDT and AST?
AST is -15h from AEDT.
What timezone is AEDT in?
AEDT operates on its local timezone.
What timezone is AST in?
AST operates on its local timezone.
Which countries use AEDT (Australian Eastern Daylight Time)?
AEDT is used in Australia (NSW, Victoria, Tasmania, ACT).
Does AEDT observe daylight saving time?
Yes, AEDT switches to AEDT during summer months.
What are some interesting facts about AEDT?
AEDT runs from the first Sunday in October to the first Sunday in April. AEDT is one hour ahead of Australian Eastern Standard Time (AEST).
Which cities are in the AST timezone?
Major cities in the AST timezone include Halifax, San Juan, Santo Domingo, Caracas, La Paz, Fredericton, Charlottetown.
What is the UTC offset for AST?
Atlantic Standard Time (AST) is at UTC-04:00. During daylight saving time, it shifts to ADT.
What should I know about the AST timezone?
Puerto Rico uses AST year-round and does not observe DST. AST is 1 hour ahead of EST.
When is it midnight in AEDT, what time is it in AST?
When it is 12:00 AM (midnight) in AEDT (AEDT), it is -15h later in AST (AST).
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See every conversion from AEDT →·See every conversion from AST →