NZDT to AST
-17hNZDT
NZDTSOURCEAST
ASTGreen rows indicate typical business hours (9 AM - 5 PM)
NZDT and AST on the World Map
The map below highlights the NZDT (New Zealand Daylight Time) and AST (Atlantic Standard Time) timezone regions across the globe.
NZDT – New Zealand Daylight Time
UTC+13:00New Zealand Daylight Time (NZDT, UTC+13:00) is New Zealand's summer time zone, one of the earliest offsets in the world.
- •NZDT runs from the last Sunday in September to the first Sunday in April.
- •NZDT is UTC+13:00 — one of the earliest time offsets used anywhere.
- •New Zealand changes its clocks two to three weeks before Australia.
- •The Chatham Islands observe UTC+13:45 during their summer time.
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.
NZDT vs AST: Offsets, DST and Best Call Times
NZDT runs on New Zealand Daylight Time (NZDT) at UTC+13:00. AST runs on Atlantic Standard Time (AST) at UTC-04:00. That puts NZDT 17 hours behind AST — a difference of -17h at the current offsets.
In practice, when it is 9:00 AM in NZDT it is 4:00 PM in AST on the previous day. Midnight in NZDT is 7:00 AM in AST. Neither zone observes daylight saving time, so the offset between them stays constant all year.
NZDT to AST time conversion table
| NZDT (NZDT) | AST (AST) | Day |
|---|---|---|
| 12:00 AM | 7:00 AM | previous day |
| 6:00 AM | 1:00 PM | previous day |
| 7:00 AM | 2:00 PM | previous day |
| 8:00 AM | 3:00 PM | previous day |
| 9:00 AM | 4:00 PM | previous day |
| 12:00 PM | 7:00 PM | previous day |
| 3:00 PM | 10:00 PM | previous day |
| 5:00 PM | 12:00 AM | same day |
| 6:00 PM | 1:00 AM | same day |
| 9:00 PM | 4:00 AM | same day |
Why people convert NZDT to AST time
- Scheduling a call from NZDT to AST: a 10:00 AM start in NZDT lands at 5:00 PM in AST the previous day, so you can confirm the slot without doing the arithmetic yourself.
- Handling a -17h gap: NZDT 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 4:00 PM in NZDT.
- Booking travel or deliveries: tracking AST local time against NZDT keeps pickup windows and arrival estimates honest across the -17h offset.
- Always state the zone abbreviation, not just the hour. "3:00 PM NZDT" is unambiguous; "3 PM" across a -17h gap is not.
- With a -17h gap there is no shared 9-to-5 window, so alternate the early start: one week NZDT takes the early slot, the next week AST does.
About NZDT (New Zealand Daylight Time)
New Zealand Daylight Time (NZDT) is the summer time zone for New Zealand, one hour ahead of New Zealand Standard Time (NZST, UTC+12:00). It runs from the last Sunday in September to the first Sunday in April, so New Zealand shifts a week or two earlier in spring than Australia. At UTC+13:00, NZDT is among the earliest offsets in the world — only Samoa, Tonga and parts of Kiribati run further ahead at certain times of year. Auckland and Wellington are 13 hours ahead of UTC during NZDT, 12 hours ahead of Sydney, and 18 hours ahead of New York. The Chatham Islands, 45 minutes further east, move to UTC+13:45.
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 NZDT and AST
With a -17h offset there is no overlap inside a normal 9 AM – 5 PM day. AST opens at 9:00 AM AST, which is 4:00 PM in NZDT, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
NZDT and AST have no shared working hours because of the -17h gap. Teams need to alternate early starts or rely on asynchronous handovers.
NZDT is 17 hours behind AST (NZDT UTC+13:00 → 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
NZDT
☀ Currently in DST
Standard: UTC+12:00 · DST: UTC+13:00
Clocks fall back on Sat, Apr 3, 2027
AST
☀ Currently in DST
Standard: UTC-04:00 · DST: UTC-03:00
Clocks fall back on Sun, Nov 1, 2026
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 NZDT and AST?
NZDT (NZDT, UTC+13:00) is 17 hours behind AST (AST, UTC-04:00). The gap is currently -17h.
How do I convert NZDT time to AST time?
Add -17h to NZDT local time. For example, 9:00 AM in NZDT is 4:00 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 -17h offset from NZDT.
What is the best time to call AST from NZDT?
There is no shared working-hours window because of the -17h gap. The closest option is 1:00 PM in NZDT, which is 8:00 PM in AST.
Which is behind, NZDT or AST?
NZDT is 17 hours behind AST. When it is 12:00 PM in NZDT it is 7:00 PM in AST.
Does daylight saving time affect the NZDT–AST difference?
Neither zone observes daylight saving time, so the -17h offset between NZDT and AST is fixed all year.
Which other cities share NZDT's time zone?
NZDT also covers Auckland, Wellington, Christchurch, Hamilton, Dunedin.
Which countries use NZDT, NZDT's zone?
NZDT is used in New Zealand.
Is there a day difference between NZDT and AST?
Sometimes. The -17h gap is large enough that 8:00 PM or later in NZDT already falls on the in AST.
What is the time difference between NZDT and AST?
AST is -17h from NZDT.
What timezone is NZDT in?
NZDT operates on its local timezone.
What timezone is AST in?
AST operates on its local timezone.
Which countries use NZDT (New Zealand Daylight Time)?
NZDT is used in New Zealand.
Does NZDT observe daylight saving time?
Yes, NZDT switches to NZDT during summer months.
What are some interesting facts about NZDT?
NZDT runs from the last Sunday in September to the first Sunday in April. NZDT is UTC+13:00 — one of the earliest time offsets used anywhere.
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 NZDT, what time is it in AST?
When it is 12:00 AM (midnight) in NZDT (NZDT), it is -17h later in AST (AST).
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See every conversion from NZDT →·See every conversion from AST →