What is the time difference between SGT and HST?

Hawaii Standard Time (HST) is 18 hours behind Singapore Time (SGT). SGT uses a UTC offset of UTC+8, while HST uses UTC-10. For example, when it's 9:00 AM in SGT, it's 3:00 PM in HST. This difference remains constant year-round since neither timezone observes daylight saving time. Use the conversion table above to see the exact time for each hour of the day.

How do I convert SGT to HST?

To convert SGT to HST, subtract 18 hours from the SGT time. For example, 9:00 AM SGT is 3:00 PM HST, and 5:00 PM SGT is 11:00 PM HST. Since neither timezone observes DST, this conversion stays the same all year. You can also use the interactive converter above for quick, accurate results.

What time is it in HST when it's noon in SGT?

When it's 12:00 PM (noon) in SGT, it's 6:00 PM in HST. This is because HST is 18 hours behind SGT. Similarly, when it's 6:00 PM in SGT, it's 12:00 AM in HST. This relationship is constant throughout the year. The color-coded conversion table above shows every hour mapped between both timezones.

How many hours behind is HST from SGT?

HST is 18 hours behind SGT. This means when it's 9:00 AM in SGT, it's 3:00 PM in HST, and when it's midnight in SGT, it's 6:00 AM in HST. This offset is constant throughout the year since neither timezone uses daylight saving time. The conversion table above provides a complete hour-by-hour mapping.

Is HST ahead or behind SGT?

HST is behind SGT by 18 hours. Clocks in HST show an earlier time than SGT, meaning the day starts later in HST relative to SGT. For example, when it's noon in SGT, it's still 6:00 PM in HST. This difference stays the same year-round.

Does SGT observe daylight saving time?

No, Singapore Time does not observe daylight saving time. The UTC offset of UTC+8 remains the same year-round, making time conversions from SGT more predictable. Countries and regions in this timezone keep their clocks unchanged regardless of the season.

Does HST observe daylight saving time?

No, Hawaii Standard Time does not observe daylight saving time. The UTC offset of UTC-10 remains the same year-round, making time conversions to HST more predictable. Countries and regions in this timezone keep their clocks unchanged regardless of the season.

What is the best time to call from SGT to HST?

The best time for a call between SGT and HST is during overlapping business hours (9 AM – 5 PM) in both timezones. To reach someone in HST during their work day, call between 3:00 AM and 11:00 AM your SGT time. Avoid calling too early or late, as the 18 hours difference means your evening could be their early morning. Check the color-coded conversion table above — green hours indicate business hours in both zones, making it easy to find the ideal time.

Do SGT and HST ever have the same time?

No, SGT and HST are always 18 hours apart and never display the same clock time simultaneously. Neither timezone observes DST, so the difference is constant year-round with no seasonal variation. The 18 hours offset is determined by their fixed positions relative to the Prime Meridian (UTC). You can always rely on this consistent difference when planning across these timezones.

SGT to HST Converter

Convert Singapore Time to Hawaii Standard Time. See the hour-by-hour conversion table below.

Timezone Details

Singapore Time

6:55 PM

Friday, April 3, 2026

SGT (UTC+08:00)

Hawaii Standard Time

12:55 AM

Friday, April 3, 2026

HST (UTC-10:00)

Difference: -18 hours

SGT DST: No

HST DST: No

24-Hour Overview

SGT — 24-hour overview

12a12a

3a3a

6a6a

9a9a

10a

11a

12p12p

3p3p

6p6p

9p9p

10p

11p

NightMorningBusinessEvening

HST — 24-hour overview

6a6a

9a9a

10a

11a

12p12p

3p3p

6p6p

9p9p

10p

11p

12a12a

3a3a

NightMorningBusinessEvening

Frequently Asked Questions

Related Conversions

HST to SGT IST to SGT SGT to IST EST to SGT SGT to EST GMT to SGT SGT to GMT

Cities in These Timezones

SGT Cities

Singapore

HST Cities

Honolulu

More Tools

Compare SGT & HST Plan a Meeting (SGT & HST)See on Map

Learn More

How Time Zones Work Understanding DST Timezone Abbreviations

External Resources

Singapore Time on Wikipedia Hawaii Standard Time on Wikipedia IANA Time Zone Database