What is the time difference between HST and SGT?

Singapore Time (SGT) is 18 hours ahead of Hawaii Standard Time (HST). HST uses a UTC offset of UTC-10, while SGT uses UTC+8. For example, when it's 9:00 AM in HST, it's 3:00 AM in SGT. 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 HST to SGT?

To convert HST to SGT, add 18 hours to the HST time. For example, 9:00 AM HST is 3:00 AM SGT, and 5:00 PM HST is 11:00 AM SGT. 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 SGT when it's noon in HST?

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

How many hours ahead is SGT from HST?

SGT is 18 hours ahead of HST. This means when it's 9:00 AM in HST, it's 3:00 AM in SGT, and when it's midnight in HST, it's 6:00 PM in SGT. 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 SGT ahead or behind HST?

SGT is ahead of HST by 18 hours. Clocks in SGT show a later time than HST, meaning the day starts earlier in SGT relative to HST. For example, when it's morning in HST, it's already afternoon or evening in SGT. This difference stays the same year-round.

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 from HST more predictable. Countries and regions in this timezone keep their clocks unchanged regardless of the season.

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 to SGT more predictable. Countries and regions in this timezone keep their clocks unchanged regardless of the season.

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

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

Do HST and SGT ever have the same time?

No, HST and SGT 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.

HST to SGT Converter

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

Timezone Details

Hawaii Standard Time

6:21 PM

Thursday, April 2, 2026

HST (UTC-10:00)

Singapore Time

12:21 PM

Friday, April 3, 2026

SGT (UTC+08:00)

Difference: +18 hours

HST DST: No

SGT DST: No

24-Hour Overview

HST — 24-hour overview

12a12a

3a3a

6a6a

9a9a

10a

11a

12p12p

3p3p

6p6p

9p9p

10p

11p

NightMorningBusinessEvening

SGT — 24-hour overview

6p6p

9p9p

10p

11p

12a12a

3a3a

6a6a

9a9a

10a

11a

12p12p

3p3p

NightMorningBusinessEvening

Frequently Asked Questions

Related Conversions

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

Cities in These Timezones

HST Cities

Honolulu

SGT Cities

Singapore

More Tools

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

Learn More

How Time Zones Work Understanding DST Timezone Abbreviations

External Resources

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