Vietnam to HST
-17hVietnam
ICTSOURCEHST
HSTGreen rows indicate typical business hours (9 AM - 5 PM)
ICT and HST on the World Map
The map below highlights the ICT (Indochina Time) and HST (Hawaii Standard Time) timezone regions across the globe.
ICT – Indochina Time
UTC+07:00Indochina Time (ICT) is the time zone for Vietnam, Thailand, Laos, and Cambodia, 7 hours ahead of UTC.
- •Bangkok is one of the most visited cities in the world.
- •ICT is 12 hours ahead of EST.
- •Thailand, Vietnam, and Cambodia all share ICT.
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).
Comparing Time Zones: Vietnam and HST
Vietnam runs on Indochina Time (ICT) at UTC+07:00. HST runs on Hawaii Standard Time (HST) at UTC-10:00. That puts Vietnam 17 hours behind HST — a difference of -17h at the current offsets.
In practice, when it is 9:00 AM in Vietnam it is 4:00 PM in HST on the previous day. Midnight in Vietnam is 7:00 AM in HST. Neither zone observes daylight saving time, so the offset between them stays constant all year.
Vietnam to HST time conversion table
| Vietnam (ICT) | HST (HST) | 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 Vietnam to HST time
- Scheduling a call from Vietnam to HST: a 10:00 AM start in Vietnam lands at 5:00 PM in HST the previous day, so you can confirm the slot without doing the arithmetic yourself.
- Handling a -17h gap: Vietnam and HST 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 HST is 4:00 PM in Vietnam.
- Watching a live event or market open: Vietnam viewers need 4:00 PM in HST to catch a 9:00 AM start there, and 5:00 PM if the event is anchored to Vietnam.
- Always state the zone abbreviation, not just the hour. "3:00 PM ICT" 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 Vietnam takes the early slot, the next week HST does.
About ICT (Indochina Time)
Indochina Time (ICT) is used across Southeast Asia including Vietnam, Thailand, Laos, and Cambodia. Indonesia (Western time, WIB) also uses UTC+07:00. ICT does not observe daylight saving time.
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.
Best time to call between Vietnam and HST
With a -17h offset there is no overlap inside a normal 9 AM – 5 PM day. HST opens at 9:00 AM HST, which is 4:00 PM in Vietnam, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
Vietnam and HST have no shared working hours because of the -17h gap. Teams need to alternate early starts or rely on asynchronous handovers.
Vietnam is 17 hours behind HST (ICT UTC+07:00 → HST UTC-10:00). There is no shared 9-to-5 window, so plan around an early or late slot. Remember to re-check around daylight-saving transitions.
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 Vietnam and HST?
Vietnam (ICT, UTC+07:00) is 17 hours behind HST (HST, UTC-10:00). The gap is currently -17h.
How do I convert Vietnam time to HST time?
Add -17h to Vietnam local time. For example, 9:00 AM in Vietnam is 4:00 PM in HST (previous day).
What time is it in HST right now?
HST uses HST at UTC-10:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -17h offset from Vietnam.
What is the best time to call HST from Vietnam?
There is no shared working-hours window because of the -17h gap. The closest option is 1:00 PM in Vietnam, which is 8:00 PM in HST.
Which is behind, Vietnam or HST?
Vietnam is 17 hours behind HST. When it is 12:00 PM in Vietnam it is 7:00 PM in HST.
Do Vietnam and HST use different time zones?
Vietnam (Vietnam) uses ICT at UTC+07:00, while HST uses HST at UTC-10:00. The IANA identifiers are Asia/Ho_Chi_Minh and Pacific/Honolulu.
Does daylight saving time affect the Vietnam–HST difference?
Neither zone observes daylight saving time, so the -17h offset between Vietnam and HST is fixed all year.
Which other cities share Vietnam's time zone?
ICT also covers Bangkok, Ho Chi Minh City, Hanoi, Jakarta, Phnom Penh, Vientiane.
Which countries use ICT, Vietnam's zone?
ICT is used in Thailand, Vietnam, Cambodia, Laos, Indonesia (WIB).
Is there a day difference between Vietnam and HST?
Sometimes. The -17h gap is large enough that 8:00 PM or later in Vietnam already falls on the in HST.
What is the time difference between Vietnam and HST?
HST is -17h from Vietnam.
What timezone is Vietnam in?
Vietnam operates on its local timezone.
What timezone is HST in?
HST operates on its local timezone.
Which countries use ICT (Indochina Time)?
ICT is used in Thailand, Vietnam, Cambodia, Laos, Indonesia (WIB).
Does ICT observe daylight saving time?
No, ICT does not observe daylight saving time and remains at UTC+07:00 year-round.
What are some interesting facts about ICT?
Bangkok is one of the most visited cities in the world. ICT is 12 hours ahead of EST.
Which cities are in the HST timezone?
Major cities in the HST timezone include Honolulu, Hilo, Kailua, Pearl City, Kapolei.
What is the UTC offset for HST?
Hawaii Standard Time (HST) is at UTC-10:00.
What should I know about the HST timezone?
Hawaii does not observe daylight saving time. HST is 5 hours behind EST in winter and 6 hours behind EDT in summer.
When is it midnight in Vietnam, what time is it in HST?
When it is 12:00 AM (midnight) in Vietnam (ICT), it is -17h later in HST (HST).
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