What is the time difference between HST and UTC?

Coordinated Universal Time (UTC) is 10 hours ahead of Hawaii Standard Time (HST). HST uses a UTC offset of UTC-10, while UTC uses UTC. For example, when it's 9:00 AM in HST, it's 7:00 PM in UTC. 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 UTC?

To convert HST to UTC, add 10 hours to the HST time. For example, 9:00 AM HST is 7:00 PM UTC, and 5:00 PM HST is 3:00 AM UTC. 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 UTC when it's noon in HST?

When it's 12:00 PM (noon) in HST, it's 10:00 PM in UTC. This is because UTC is 10 hours ahead of HST. Similarly, when it's 6:00 PM in HST, it's 4:00 AM in UTC. 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 UTC from HST?

UTC is 10 hours ahead of HST. This means when it's 9:00 AM in HST, it's 7:00 PM in UTC, and when it's midnight in HST, it's 10:00 AM in UTC. 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 UTC ahead or behind HST?

UTC is ahead of HST by 10 hours. Clocks in UTC show a later time than HST, meaning the day starts earlier in UTC relative to HST. For example, when it's morning in HST, it's already afternoon or evening in UTC. 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 UTC observe daylight saving time?

No, Coordinated Universal Time does not observe daylight saving time. The UTC offset of UTC remains the same year-round, which simplifies time conversions. Regions using UTC keep their clocks unchanged regardless of the season.

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

The best time for a call between HST and UTC is during overlapping business hours (9 AM – 5 PM) in both timezones. To reach someone in UTC during their work day, call between 11:00 PM and 7:00 AM your HST time. Avoid calling too early or late, as the 10 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 UTC ever have the same time?

No, HST and UTC are always 10 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 10 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 UTC Converter

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

Timezone Details

Hawaii Standard Time

7:10 PM

Thursday, April 2, 2026

HST (UTC-10:00)

UTC

5:10 AM

Friday, April 3, 2026

UTC (UTC+00:00)

Difference: +10 hours

HST DST: No

24-Hour Overview

HST — 24-hour overview

12a12a

3a3a

6a6a

9a9a

10a

11a

12p12p

3p3p

6p6p

9p9p

10p

11p

NightMorningBusinessEvening

UTC — 24-hour overview

10a10a

11a

12p

1p1p

4p4p

7p7p

10p10p

11p

12a

1a1a

4a4a

7a7a

NightMorningBusinessEvening

Frequently Asked Questions

Related Conversions

UTC to HST

Cities in These Timezones

HST Cities

Honolulu

More Tools

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

Learn More

How Time Zones Work Understanding DST Timezone Abbreviations

External Resources

Hawaii Standard Time on Wikipedia Coordinated Universal Time on Wikipedia IANA Time Zone Database