Singapore to HST
-18hSingapore
SGTSOURCEHST
HSTGreen rows indicate typical business hours (9 AM - 5 PM)
SGT and HST on the World Map
The map below highlights the SGT (Singapore Standard Time) and HST (Hawaii Standard Time) timezone regions across the globe.
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.
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).
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.
Singapore to HST Time Difference – Complete Guide
Singapore runs on Singapore Standard Time (SGT) at UTC+08:00. HST runs on Hawaii Standard Time (HST) at UTC-10:00. That puts Singapore 18 hours behind HST — a difference of -18h at the current offsets.
In practice, when it is 9:00 AM in Singapore it is 3:00 PM in HST on the previous day. Midnight in Singapore is 6:00 AM in HST. Neither zone observes daylight saving time, so the offset between them stays constant all year.
Singapore to HST time conversion table
| Singapore (SGT) | HST (HST) | Day |
|---|---|---|
| 12:00 AM | 6:00 AM | previous day |
| 6:00 AM | 12:00 PM | previous day |
| 7:00 AM | 1:00 PM | previous day |
| 8:00 AM | 2:00 PM | previous day |
| 9:00 AM | 3:00 PM | previous day |
| 12:00 PM | 6:00 PM | previous day |
| 3:00 PM | 9:00 PM | previous day |
| 5:00 PM | 11:00 PM | previous day |
| 6:00 PM | 12:00 AM | same day |
| 9:00 PM | 3:00 AM | same day |
Why people convert Singapore to HST time
- Scheduling a call from Singapore to HST: a 10:00 AM start in Singapore lands at 4:00 PM in HST the previous day, so you can confirm the slot without doing the arithmetic yourself.
- Handling a -18h gap: Singapore 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 3:00 PM in Singapore.
- Watching a live event or market open: Singapore viewers need 3:00 PM in HST to catch a 9:00 AM start there, and 6:00 PM if the event is anchored to Singapore.
- Always state the zone abbreviation, not just the hour. "3:00 PM SGT" 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 Singapore takes the early slot, the next week HST does.
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.
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 Singapore and HST
With a -18h offset there is no overlap inside a normal 9 AM – 5 PM day. HST opens at 9:00 AM HST, which is 3:00 PM in Singapore, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
Singapore and HST have no shared working hours because of the -18h gap. Teams need to alternate early starts or rely on asynchronous handovers.
Singapore is 18 hours behind HST (SGT UTC+08:00 → 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 Singapore and HST?
Singapore (SGT, UTC+08:00) is 18 hours behind HST (HST, UTC-10:00). The gap is currently -18h.
How do I convert Singapore time to HST time?
Add -18h to Singapore local time. For example, 9:00 AM in Singapore is 3:00 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 -18h offset from Singapore.
What is the best time to call HST from Singapore?
There is no shared working-hours window because of the -18h gap. The closest option is 1:00 PM in Singapore, which is 7:00 PM in HST.
Which is behind, Singapore or HST?
Singapore is 18 hours behind HST. When it is 12:00 PM in Singapore it is 6:00 PM in HST.
Do Singapore and HST use different time zones?
Singapore (Singapore) uses SGT at UTC+08:00, while HST uses HST at UTC-10:00. The IANA identifiers are Asia/Singapore and Pacific/Honolulu.
Does daylight saving time affect the Singapore–HST difference?
Neither zone observes daylight saving time, so the -18h offset between Singapore and HST is fixed all year.
Which other cities share Singapore's time zone?
SGT also covers Singapore.
Which countries use SGT, Singapore's zone?
SGT is used in Singapore.
Is there a day difference between Singapore and HST?
Sometimes. The -18h gap is large enough that 8:00 PM or later in Singapore already falls on the in HST.
What is the time difference between Singapore and HST?
HST is -18h from Singapore.
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 timezone is HST in?
HST operates on its local timezone.
What are the business hours in Singapore?
Standard business hours in Singapore are 9:00 AM - 6:00 PM SGT.
Which countries use SGT (Singapore Standard Time)?
SGT is used in Singapore.
Does SGT observe daylight saving time?
No, SGT does not observe daylight saving time and remains at UTC+08:00 year-round.
What are some interesting facts about SGT?
Singapore uses UTC+08:00 despite being at about 104°E longitude (closer to UTC+07:00). Singapore does not observe daylight saving time.
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 Singapore, what time is it in HST?
When it is 12:00 AM (midnight) in Singapore (SGT), it is -18h later in HST (HST).
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