HST to NZDT
+23hHST
HSTSOURCENZDT
NZDTGreen rows indicate typical business hours (9 AM - 5 PM)
HST and NZDT on the World Map
The map below highlights the HST (Hawaii Standard Time) and NZDT (New Zealand Daylight Time) timezone regions across the globe.
HST – Hawaii Standard Time
UTC-10:00Hawaii Standard Time (HST) is the time zone for the Hawaiian Islands, 10 hours behind UTC.
- •Hawaii does not observe daylight saving time.
- •HST is 5 hours behind EST in winter and 6 hours behind EDT in summer.
- •Hawaii is one of only two US states that don't observe DST (the other is Arizona).
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.
Comparing Time Zones: HST and NZDT
HST runs on Hawaii Standard Time (HST) at UTC-10:00. NZDT runs on New Zealand Daylight Time (NZDT) at UTC+13:00. That puts HST 23 hours ahead of NZDT — a difference of +23h at the current offsets.
In practice, when it is 9:00 AM in HST it is 8:00 AM in NZDT on the next day. Midnight in HST is 11:00 PM in NZDT. Neither zone observes daylight saving time, so the offset between them stays constant all year.
HST to NZDT time conversion table
| HST (HST) | NZDT (NZDT) | Day |
|---|---|---|
| 12:00 AM | 11:00 PM | same day |
| 6:00 AM | 5:00 AM | next day |
| 7:00 AM | 6:00 AM | next day |
| 8:00 AM | 7:00 AM | next day |
| 9:00 AM | 8:00 AM | next day |
| 12:00 PM | 11:00 AM | next day |
| 3:00 PM | 2:00 PM | next day |
| 5:00 PM | 4:00 PM | next day |
| 6:00 PM | 5:00 PM | next day |
| 9:00 PM | 8:00 PM | next day |
Why people convert HST to NZDT time
- Scheduling a call from HST to NZDT: a 10:00 AM start in HST lands at 9:00 AM in NZDT the next day, so you can confirm the slot without doing the arithmetic yourself.
- Handling a +23h gap: HST and NZDT 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 NZDT is 8:00 AM in HST.
- Coordinating a HST-based team with NZDT 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 HST" is unambiguous; "3 PM" across a +23h gap is not.
- With a +23h gap there is no shared 9-to-5 window, so alternate the early start: one week HST takes the early slot, the next week NZDT does.
About HST (Hawaii Standard Time)
Hawaii Standard Time (HST) is used in the state of Hawaii and does not observe daylight saving time. This makes HST one of the most consistent time zones in the US. The Hawaiian Islands are among the last places on Earth to see a new calendar day.
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.
Best time to call between HST and NZDT
With a +23h offset there is no overlap inside a normal 9 AM – 5 PM day. NZDT opens at 9:00 AM NZDT, which is 8:00 AM in HST, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
HST and NZDT have no shared working hours because of the +23h gap. Teams need to alternate early starts or rely on asynchronous handovers.
HST is 23 hours ahead of NZDT (HST UTC-10:00 → NZDT UTC+13:00). 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
HST
Does not observe DST
NZDT
☀ Currently in DST
Standard: UTC+12:00 · DST: UTC+13:00
Clocks fall back on Sat, Apr 3, 2027
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 HST and NZDT?
HST (HST, UTC-10:00) is 23 hours ahead of NZDT (NZDT, UTC+13:00). The gap is currently +23h.
How do I convert HST time to NZDT time?
Add +23h to HST local time. For example, 9:00 AM in HST is 8:00 AM in NZDT (next day).
What time is it in NZDT right now?
NZDT uses NZDT at UTC+13:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +23h offset from HST.
What is the best time to call NZDT from HST?
There is no shared working-hours window because of the +23h gap. The closest option is 1:00 PM in HST, which is 12:00 PM in NZDT.
Which is ahead, HST or NZDT?
HST is 23 hours ahead of NZDT. When it is 12:00 PM in HST it is 11:00 AM in NZDT.
Does daylight saving time affect the HST–NZDT difference?
Neither zone observes daylight saving time, so the +23h offset between HST and NZDT is fixed all year.
Which other cities share HST's time zone?
HST also covers Honolulu, Hilo, Kailua, Pearl City, Kapolei.
Which countries use HST, HST's zone?
HST is used in United States (Hawaii).
Is there a day difference between HST and NZDT?
Sometimes. The +23h gap is large enough that 8:00 PM or later in HST already falls on the next day in NZDT.
What is the time difference between HST and NZDT?
NZDT is +23h from HST.
What timezone is HST in?
HST operates on its local timezone.
What timezone is NZDT in?
NZDT operates on its local timezone.
Which countries use HST (Hawaii Standard Time)?
HST is used in United States (Hawaii).
Does HST observe daylight saving time?
No, HST does not observe daylight saving time and remains at UTC-10:00 year-round.
What are some interesting facts about HST?
Hawaii does not observe daylight saving time. HST is 5 hours behind EST in winter and 6 hours behind EDT in summer.
Which cities are in the NZDT timezone?
Major cities in the NZDT timezone include Auckland, Wellington, Christchurch, Hamilton, Dunedin.
What is the UTC offset for NZDT?
New Zealand Daylight Time (NZDT) is at UTC+13:00. During daylight saving time, it shifts to NZDT.
What should I know about the NZDT timezone?
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.
When is it midnight in HST, what time is it in NZDT?
When it is 12:00 AM (midnight) in HST (HST), it is +23h later in NZDT (NZDT).
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