HST to Singapore
+18hHST
HSTSOURCESingapore
SGTGreen rows indicate typical business hours (9 AM - 5 PM)
HST and SGT on the World Map
The map below highlights the HST (Hawaii Standard Time) and SGT (Singapore Standard 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).
SGT – Singapore Standard Time
UTC+08:00Singapore Standard Time (SGT) is the time zone for Singapore, 8 hours ahead of UTC.
- •Singapore uses UTC+08:00 despite being at about 104°E longitude (closer to UTC+07:00).
- •Singapore does not observe daylight saving time.
- •The Singapore Exchange (SGX) operates on SGT.
About Singapore
WikipediaSingapore Standard Time (SGT) is 8 hours ahead of GMT. As Asia's leading financial hub, Singapore bridges business hours between Europe and Australia.
The city-state has the world's highest percentage of millionaires, with 1 in 6 households.
Everything You Need to Know About HST and Singapore Time
HST runs on Hawaii Standard Time (HST) at UTC-10:00. Singapore runs on Singapore Standard Time (SGT) at UTC+08:00. That puts HST 18 hours ahead of Singapore — a difference of +18h at the current offsets.
In practice, when it is 9:00 AM in HST it is 3:00 AM in Singapore on the next day. Midnight in HST is 6:00 PM in Singapore. Neither zone observes daylight saving time, so the offset between them stays constant all year.
HST to Singapore time conversion table
| HST (HST) | Singapore (SGT) | Day |
|---|---|---|
| 12:00 AM | 6:00 PM | same day |
| 6:00 AM | 12:00 AM | next day |
| 7:00 AM | 1:00 AM | next day |
| 8:00 AM | 2:00 AM | next day |
| 9:00 AM | 3:00 AM | next day |
| 12:00 PM | 6:00 AM | next day |
| 3:00 PM | 9:00 AM | next day |
| 5:00 PM | 11:00 AM | next day |
| 6:00 PM | 12:00 PM | next day |
| 9:00 PM | 3:00 PM | next day |
Why people convert HST to Singapore time
- Scheduling a call from HST to Singapore: a 10:00 AM start in HST lands at 4:00 AM in Singapore the next day, so you can confirm the slot without doing the arithmetic yourself.
- Handling a +18h gap: HST and Singapore 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 Singapore is 3:00 AM in HST.
- Keeping family and friends in sync: knowing that 8:00 PM in HST is 2:00 PM in Singapore makes it easy to avoid calling at 3 AM.
- Always state the zone abbreviation, not just the hour. "3:00 PM HST" is unambiguous; "3 PM" across a +18h gap is not.
- With a +18h gap there is no shared 9-to-5 window, so alternate the early start: one week HST takes the early slot, the next week Singapore 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 SGT (Singapore Standard Time)
Singapore Standard Time (SGT) is used in Singapore year-round. Singapore does not observe daylight saving time. Despite being geographically close to the UTC+07:00 zone, Singapore uses UTC+08:00 to align with major trading partners like China, Hong Kong, and Malaysia. Singapore is a major global financial hub.
Best time to call between HST and Singapore
With a +18h offset there is no overlap inside a normal 9 AM – 5 PM day. Singapore opens at 9:00 AM SGT, which is 3:00 AM in HST, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
HST and Singapore have no shared working hours because of the +18h gap. Teams need to alternate early starts or rely on asynchronous handovers.
HST is 18 hours ahead of Singapore (HST UTC-10:00 → SGT UTC+08:00). 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 HST and Singapore?
HST (HST, UTC-10:00) is 18 hours ahead of Singapore (SGT, UTC+08:00). The gap is currently +18h.
How do I convert HST time to Singapore time?
Add +18h to HST local time. For example, 9:00 AM in HST is 3:00 AM in Singapore (next day).
What time is it in Singapore right now?
Singapore uses SGT at UTC+08:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +18h offset from HST.
What is the best time to call Singapore from HST?
There is no shared working-hours window because of the +18h gap. The closest option is 1:00 PM in HST, which is 7:00 AM in Singapore.
Which is ahead, HST or Singapore?
HST is 18 hours ahead of Singapore. When it is 12:00 PM in HST it is 6:00 AM in Singapore.
Do HST and Singapore use different time zones?
HST uses HST at UTC-10:00, while Singapore (Singapore) uses SGT at UTC+08:00. The IANA identifiers are Pacific/Honolulu and Asia/Singapore.
Does daylight saving time affect the HST–Singapore difference?
Neither zone observes daylight saving time, so the +18h offset between HST and Singapore 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 Singapore?
Sometimes. The +18h gap is large enough that 8:00 PM or later in HST already falls on the next day in Singapore.
What is the time difference between HST and Singapore?
Singapore is +18h from HST.
What timezone is HST in?
HST operates on its local timezone.
What timezone is Singapore in?
Singapore Standard Time (SGT) is 8 hours ahead of GMT. As Asia's leading financial hub, Singapore bridges business hours between Europe and Australia.
What are the business hours in Singapore?
Standard business hours in Singapore are 9:00 AM - 6:00 PM SGT.
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 SGT timezone?
Major cities in the SGT timezone include Singapore.
What is the UTC offset for SGT?
Singapore Standard Time (SGT) is at UTC+08:00.
What should I know about the SGT timezone?
Singapore uses UTC+08:00 despite being at about 104°E longitude (closer to UTC+07:00). Singapore does not observe daylight saving time.
When is it midnight in HST, what time is it in Singapore?
When it is 12:00 AM (midnight) in HST (HST), it is +18h later in Singapore (SGT).
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