HST to Istanbul
+13hHST
HSTSOURCEIstanbul
TRTGreen rows indicate typical business hours (9 AM - 5 PM)
HST and TRT on the World Map
The map below highlights the HST (Hawaii Standard Time) and TRT (Turkey Time) timezone regions across the globe.
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).
TRT – Turkey Time
UTC+03:00Turkey Time (TRT, UTC+03:00) is the single time zone used across Turkey, fixed year round since 2016.
- •Turkey has used a permanent UTC+03:00 since September 2016.
- •TRT is level with Moscow Standard Time and Arabia Standard Time all year.
- •Because Turkey kept summer time permanently, western cities see very late winter sunrises.
- •Turkey previously observed daylight saving time from 1973 to 2016.
About Istanbul
WikipediaIstanbul operates on Turkey Time (TRT), UTC+3 year-round. As a transcontinental city, Istanbul bridges European and Asian business hours.
The Grand Bazaar is one of the world's oldest and largest covered markets with 4,000+ shops.
HST to Istanbul Time Difference – Complete Guide
HST runs on Hawaii Standard Time (HST) at UTC-10:00. Istanbul runs on Türkiye Standard Time (TRT) at UTC+03:00. That puts HST 13 hours ahead of Istanbul — a difference of +13h at the current offsets.
In practice, when it is 9:00 AM in HST it is 10:00 PM in Istanbul. Midnight in HST is 1:00 PM in Istanbul. Neither zone observes daylight saving time, so the offset between them stays constant all year.
HST to Istanbul time conversion table
| HST (HST) | Istanbul (TRT) | Day |
|---|---|---|
| 12:00 AM | 1:00 PM | same day |
| 6:00 AM | 7:00 PM | same day |
| 7:00 AM | 8:00 PM | same day |
| 8:00 AM | 9:00 PM | same day |
| 9:00 AM | 10:00 PM | same day |
| 12:00 PM | 1:00 AM | next day |
| 3:00 PM | 4:00 AM | next day |
| 5:00 PM | 6:00 AM | next day |
| 6:00 PM | 7:00 AM | next day |
| 9:00 PM | 10:00 AM | next day |
Why people convert HST to Istanbul time
- Scheduling a call from HST to Istanbul: a 10:00 AM start in HST lands at 11:00 PM in Istanbul, so you can confirm the slot without doing the arithmetic yourself.
- Handling a +13h gap: HST and Istanbul 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 Istanbul is 10:00 PM in HST.
- Keeping family and friends in sync: knowing that 8:00 PM in HST is 9:00 AM in Istanbul makes it easy to avoid calling at 3 AM.
- Always state the zone abbreviation, not just the hour. "3:00 PM HST" is unambiguous; "3 PM" across a +13h gap is not.
- With a +13h gap there is no shared 9-to-5 window, so alternate the early start: one week HST takes the early slot, the next week Istanbul does.
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.
About TRT (Turkey Time)
Turkey Time (TRT) is fixed at UTC+03:00 all year. Turkey abolished seasonal clock changes in September 2016, moving to a permanent UTC+03:00 so the whole country stays on what was formerly summer time. That leaves Istanbul, which sits close to 29°E, on an offset well ahead of its solar time — sunrise in mid-winter comes after 08:30 local. TRT shares its offset with Moscow Standard Time, Arabia Standard Time and East Africa Time, so Istanbul is level with Moscow and Riyadh all year and one hour ahead of Central European Time during the European winter.
Best time to call between HST and Istanbul
With a +13h offset there is no overlap inside a normal 9 AM – 5 PM day. Istanbul opens at 9:00 AM TRT, which is 10:00 PM in HST, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
HST and Istanbul have no shared working hours because of the +13h gap. Teams need to alternate early starts or rely on asynchronous handovers.
HST is 13 hours ahead of Istanbul (HST UTC-10:00 → TRT UTC+03:00). 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 HST and Istanbul?
HST (HST, UTC-10:00) is 13 hours ahead of Istanbul (TRT, UTC+03:00). The gap is currently +13h.
How do I convert HST time to Istanbul time?
Add +13h to HST local time. For example, 9:00 AM in HST is 10:00 PM in Istanbul.
What time is it in Istanbul right now?
Istanbul uses TRT at UTC+03:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +13h offset from HST.
What is the best time to call Istanbul from HST?
There is no shared working-hours window because of the +13h gap. The closest option is 1:00 PM in HST, which is 2:00 AM in Istanbul.
Which is ahead, HST or Istanbul?
HST is 13 hours ahead of Istanbul. When it is 12:00 PM in HST it is 1:00 AM in Istanbul.
Do HST and Istanbul use different time zones?
HST uses HST at UTC-10:00, while Istanbul (Turkey) uses TRT at UTC+03:00. The IANA identifiers are Pacific/Honolulu and Europe/Istanbul.
Does daylight saving time affect the HST–Istanbul difference?
Neither zone observes daylight saving time, so the +13h offset between HST and Istanbul is fixed all year.
Which other cities share HST's time zone?
HST also covers Honolulu, Hilo, Kailua, Pearl City, Kapolei.
Which countries use HST, HST's zone?
HST is used in United States (Hawaii).
Is there a day difference between HST and Istanbul?
Sometimes. The +13h gap is large enough that 8:00 PM or later in HST already falls on the next day in Istanbul.
What is the time difference between HST and Istanbul?
Istanbul is +13h from HST.
What timezone is HST in?
HST operates on its local timezone.
What timezone is Istanbul in?
Istanbul operates on Turkey Time (TRT), UTC+3 year-round. As a transcontinental city, Istanbul bridges European and Asian business hours.
What are the business hours in Istanbul?
Standard business hours in Istanbul are 9:00 AM - 6:00 PM TRT.
Which countries use HST (Hawaii Standard Time)?
HST is used in United States (Hawaii).
Does HST observe daylight saving time?
No, HST does not observe daylight saving time and remains at UTC-10:00 year-round.
What are some interesting facts about HST?
Hawaii does not observe daylight saving time. HST is 5 hours behind EST in winter and 6 hours behind EDT in summer.
Which cities are in the TRT timezone?
Major cities in the TRT timezone include Istanbul, Ankara, Izmir, Bursa, Antalya.
What is the UTC offset for TRT?
Turkey Time (TRT) is at UTC+03:00.
What should I know about the TRT timezone?
Turkey has used a permanent UTC+03:00 since September 2016. TRT is level with Moscow Standard Time and Arabia Standard Time all year.
When is it midnight in HST, what time is it in Istanbul?
When it is 12:00 AM (midnight) in HST (HST), it is +13h later in Istanbul (TRT).
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