AST to AEDT
+15hAST
ASTSOURCEAEDT
AEDTGreen rows indicate typical business hours (9 AM - 5 PM)
AST and AEDT on the World Map
The map below highlights the AST (Atlantic Standard Time) and AEDT (Australian Eastern Daylight Time) timezone regions across the globe.
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 – 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.
Understanding the +15h Gap: AST vs AEDT
AST runs on Atlantic Standard Time (AST) at UTC-04:00. AEDT runs on Australian Eastern Daylight Time (AEDT) at UTC+11:00. That puts AST 15 hours ahead of AEDT — a difference of +15h at the current offsets.
In practice, when it is 9:00 AM in AST it is 12:00 AM in AEDT on the next day. Midnight in AST is 3:00 PM in AEDT. Neither zone observes daylight saving time, so the offset between them stays constant all year.
AST to AEDT time conversion table
| AST (AST) | AEDT (AEDT) | Day |
|---|---|---|
| 12:00 AM | 3:00 PM | same day |
| 6:00 AM | 9:00 PM | same day |
| 7:00 AM | 10:00 PM | same day |
| 8:00 AM | 11:00 PM | same day |
| 9:00 AM | 12:00 AM | next day |
| 12:00 PM | 3:00 AM | next day |
| 3:00 PM | 6:00 AM | next day |
| 5:00 PM | 8:00 AM | next day |
| 6:00 PM | 9:00 AM | next day |
| 9:00 PM | 12:00 PM | next day |
Why people convert AST to AEDT time
- Scheduling a call from AST to AEDT: a 10:00 AM start in AST lands at 1:00 AM in AEDT the next day, so you can confirm the slot without doing the arithmetic yourself.
- Handling a +15h gap: AST and AEDT 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 AEDT is 12:00 AM in AST.
- Coordinating a AST-based team with AEDT contacts: quoting times in the other side's local clock — not your own — removes the single biggest source of missed meetings.
- Always state the zone abbreviation, not just the hour. "3:00 PM AST" 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 AST takes the early slot, the next week AEDT does.
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.
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.
Best time to call between AST and AEDT
With a +15h offset there is no overlap inside a normal 9 AM – 5 PM day. AEDT opens at 9:00 AM AEDT, which is 12:00 AM in AST, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
AST and AEDT have no shared working hours because of the +15h gap. Teams need to alternate early starts or rely on asynchronous handovers.
AST is 15 hours ahead of AEDT (AST UTC-04:00 → AEDT UTC+11:00). 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
AST
☀ Currently in DST
Standard: UTC-04:00 · DST: UTC-03:00
Clocks fall back on Sun, Nov 1, 2026
AEDT
❄ Currently in Standard Time
Standard: UTC+10:00 · DST: UTC+11:00
Clocks spring forward on Sat, Oct 3, 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 AST and AEDT?
AST (AST, UTC-04:00) is 15 hours ahead of AEDT (AEDT, UTC+11:00). The gap is currently +15h.
How do I convert AST time to AEDT time?
Add +15h to AST local time. For example, 9:00 AM in AST is 12:00 AM in AEDT (next day).
What time is it in AEDT right now?
AEDT uses AEDT at UTC+11:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +15h offset from AST.
What is the best time to call AEDT from AST?
There is no shared working-hours window because of the +15h gap. The closest option is 1:00 PM in AST, which is 4:00 AM in AEDT.
Which is ahead, AST or AEDT?
AST is 15 hours ahead of AEDT. When it is 12:00 PM in AST it is 3:00 AM in AEDT.
Does daylight saving time affect the AST–AEDT difference?
Neither zone observes daylight saving time, so the +15h offset between AST and AEDT is fixed all year.
Which other cities share AST's time zone?
AST also covers Halifax, San Juan, Santo Domingo, Caracas, La Paz, Fredericton, Charlottetown.
Which countries use AST, AST's zone?
AST is used in Canada (Atlantic provinces), Puerto Rico, US Virgin Islands, Dominican Republic, Venezuela, Bolivia, Barbados, Trinidad and Tobago.
Is there a day difference between AST and AEDT?
Sometimes. The +15h gap is large enough that 8:00 PM or later in AST already falls on the next day in AEDT.
What is the time difference between AST and AEDT?
AEDT is +15h from AST.
What timezone is AST in?
AST operates on its local timezone.
What timezone is AEDT in?
AEDT operates on its local timezone.
Which countries use AST (Atlantic Standard Time)?
AST is used in Canada (Atlantic provinces), Puerto Rico, US Virgin Islands, Dominican Republic, Venezuela, Bolivia, and 2 more countries.
Does AST observe daylight saving time?
Yes, AST switches to ADT during summer months.
What are some interesting facts about AST?
Puerto Rico uses AST year-round and does not observe DST. AST is 1 hour ahead of EST.
Which cities are in the AEDT timezone?
Major cities in the AEDT timezone include Sydney, Melbourne, Canberra, Hobart, Newcastle.
What is the UTC offset for AEDT?
Australian Eastern Daylight Time (AEDT) is at UTC+11:00. During daylight saving time, it shifts to AEDT.
What should I know about the AEDT timezone?
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).
When is it midnight in AST, what time is it in AEDT?
When it is 12:00 AM (midnight) in AST (AST), it is +15h later in AEDT (AEDT).
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See every conversion from AST →·See every conversion from AEDT →