SGT to HST Converter
Convert time between Singapore Standard Time (SGT) and Hawaii Standard Time (HST)
Singapore Standard Time (SGT)
Hawaii Standard Time (HST)
Time Difference
Hawaii Standard Time (HST) is 0 hours ahead of Singapore Standard Time (SGT)
Select Date
Select Time
Quick Reference
| SGT | HST |
|---|---|
| 10:00 | 16:00 |
| 12:00 | 18:00 |
| 14:00 | 20:00 |
| 16:00 | 22:00 |
| 18:00 | 00:00 |
| 20:00 | 02:00 |
| 22:00 | 04:00 |
| 00:00 | 06:00 |
| 02:00 | 08:00 |
| 04:00 | 10:00 |
| 06:00 | 12:00 |
| 08:00 | 14:00 |
Top 10 Most Common Time Zones
| Abbreviation | Full Name | UTC Offset | Typical Use |
|---|---|---|---|
| UTC | Coordinated Universal Time | UTC ±0 | Global reference standard (servers, logs, APIs) |
| EST / EDT | Eastern (US) Time | UTC −5 / −4 | New York, Toronto — North American business hub |
| CST / CDT | Central (US) Time | UTC −6 / −5 | Chicago, Dallas — US central business region |
| PST / PDT | Pacific (US) Time | UTC −8 / −7 | San Francisco, Los Angeles — tech industry standard |
| GMT / BST | Greenwich Mean / British Summer Time | UTC 0 / +1 | UK, used globally as a reference with UTC |
| CET / CEST | Central European (Summer) Time | UTC +1 / +2 | Paris, Berlin, Amsterdam — EU business core |
| IST | India Standard Time | UTC +5:30 | India — major IT & outsourcing region |
| CST | China Standard Time | UTC +8 | Beijing, Shanghai — East Asia business hub |
| JST | Japan Standard Time | UTC +9 | Tokyo — finance & tech hub |
| AEST / AEDT | Australian Eastern (Daylight) Time | UTC +10 / +11 | Sydney, Melbourne — APAC regional business |
Why Time Zone Abbreviations Are Ambiguous
Unlike standardized identifiers (like America/New_York or Europe/London from the IANA tz database), abbreviations such as "CST" or "IST" are not globally unique. They can refer to different time zones depending on context — country, region, or even time of year (due to daylight saving time).
Common Ambiguous Time Zone Abbreviations
| Abbrev. | Common Meaning(s) | UTC Offset | Region(s) |
|---|---|---|---|
| CST | Central Standard Time / China Standard Time / Cuba Standard Time | UTC−6 / UTC+8 / UTC−5 | North America, China, Cuba |
| IST | Indian Standard Time / Irish Standard Time / Israel Standard Time | UTC+5:30 / UTC+1 / UTC+2 | India, Ireland, Israel |
| AST | Atlantic Standard Time / Arabia Standard Time | UTC−4 / UTC+3 | Caribbean, Canada, Middle East |
| PST | Pacific Standard Time / Philippine Standard Time | UTC−8 / UTC+8 | North America, Philippines |
| EST | Eastern Standard Time (North America / Australia) | UTC−5 / UTC+10 | North America, Australia |
✅ Best Practice
To avoid ambiguity, always:
- Use IANA tz identifiers — e.g.,
America/New_Yorkinstead of "EST" - Specify UTC offset explicitly — e.g.,
UTC−5when abbreviations must be used - Include the full timezone name — e.g., "Eastern Standard Time (EST)" with UTC offset
About SGT to HST Time Conversion
Converting time between Singapore Standard Time (SGT) and Hawaii Standard Time (HST) is essential for coordinating across one of the largest time gaps in regular use. SGT is UTC+8 year-round, while HST is UTC-10, placing Singapore 18 hours ahead of Hawaii. Neither side observes daylight saving, so the 18-hour offset is constant 365 days a year.
This time zone converter uses the IANA timezone database to ensure accurate calculations. Singapore never observes DST and Hawaii skipped DST in 1947, so SGT-HST is one of the most stable cross-Pacific conversions. Whether you're scheduling meetings between Singapore and Honolulu, planning travel through the Pacific, or coordinating with family or partners in the Hawaiian Islands, our converter provides reliable results.
Common Use Cases for SGT to HST Conversion
Business & Work
- Scheduling meetings between Singapore and Honolulu offices or partners
- Coordinating logistics and shipping across the Asia-Pacific
- Planning conference calls bridging Southeast Asia and the central Pacific
Personal & Travel
- Planning Pacific travel itineraries between Singapore and the Hawaiian Islands
- Coordinating with family and friends in Honolulu, Maui or Hilo
- Scheduling virtual events bridging Asia and Hawaii
Time Zone Information
Singapore Standard Time (SGT)
- UTC Offset: UTC+8
- IANA Timezone: Asia/Singapore
- Daylight Saving: No daylight saving time (consistent year-round)
- Major Cities: Singapore
- Coverage: Republic of Singapore
Hawaii Standard Time (HST)
- UTC Offset: UTC-10
- IANA Timezone: Pacific/Honolulu
- Daylight Saving: No daylight saving time (Hawaii does not observe DST)
- Major Cities: Honolulu, Hilo, Kailua, Kaneohe, Pearl City, Waipahu
- Coverage: State of Hawaii and parts of the central Pacific
Quick Reference: SGT to HST
Remember: HST is exactly 18 hours behind SGT, all year. Neither zone observes daylight saving so the offset never changes.
Frequently Asked Questions
What is the time difference between SGT and HST?
Singapore Standard Time (SGT) is UTC+8, while Hawaii Standard Time (HST) is UTC-10. SGT is exactly 18 hours ahead of HST. When it is 12:00 PM in Singapore, it is 6:00 PM the previous day in Honolulu.
When does this SGT to HST conversion apply?
All year round. Hawaii does not observe daylight saving and Singapore never has, so the 18-hour offset is constant 12 months a year — one of the largest stable cross-Pacific gaps.
Does Hawaii observe daylight saving time?
No. Hawaii opted out of US daylight saving in 1947 and has stayed on HST year-round ever since. Combined with Singapore also having no DST, the SGT-HST offset is unusually stable.
What are the best times for SGT-HST business calls?
With an 18-hour gap, live overlap is extremely narrow. Singapore very early morning (3:00 to 6:00 AM SGT) maps to Hawaii afternoon (9:00 AM to 12:00 PM HST the previous day). For a Hawaii morning slot, late Singapore evening into the night (9:00 to 11:00 PM SGT) reaches 3:00 to 5:00 AM HST same day.
Which countries or regions use HST?
HST is observed across the US state of Hawaii year-round. Major locations include Honolulu, Hilo, Kailua, Kaneohe, Pearl City and Waipahu. The UTC-10 offset is also used by parts of French Polynesia (Tahiti) and the Cook Islands.
Which countries or regions use SGT?
Singapore Standard Time is used only in the Republic of Singapore. UTC+8 is shared with Malaysia, Western Australia, Hong Kong, the Philippines and most of mainland China.
Pro Tips
- • HST is exactly 18 hours behind SGT, all year. Singapore noon is 6 PM the previous day in Hawaii.
- • Neither zone observes DST, so the offset is fixed and predictable.
- • Almost any "morning" in one zone is the previous afternoon in the other — always include date plus time in scheduling messages.
- • For a Hawaii morning slot, late Singapore evening (9:00 to 11:00 PM SGT) works.
- • For a Singapore morning slot, prepare to take a late-afternoon Hawaii call from your previous day.
- • Use IANA identifiers Asia/Singapore and Pacific/Honolulu in calendars — both are stable so the offset stays put.