Istanbul to HST
-13hIstanbul
TRTSOURCEHST
HSTGreen rows indicate typical business hours (9 AM - 5 PM)
TRT and HST on the World Map
The map below highlights the TRT (Turkey Time) and HST (Hawaii Standard Time) timezone regions across the globe.
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.
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).
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.
Istanbul to HST Time Difference – Complete Guide
Istanbul runs on Türkiye Standard Time (TRT) at UTC+03:00. HST runs on Hawaii Standard Time (HST) at UTC-10:00. That puts Istanbul 13 hours behind HST — a difference of -13h at the current offsets.
In practice, when it is 9:00 AM in Istanbul it is 8:00 PM in HST on the previous day. Midnight in Istanbul is 11:00 AM in HST. Neither zone observes daylight saving time, so the offset between them stays constant all year.
Istanbul to HST time conversion table
| Istanbul (TRT) | HST (HST) | Day |
|---|---|---|
| 12:00 AM | 11:00 AM | previous day |
| 6:00 AM | 5:00 PM | previous day |
| 7:00 AM | 6:00 PM | previous day |
| 8:00 AM | 7:00 PM | previous day |
| 9:00 AM | 8:00 PM | previous day |
| 12:00 PM | 11:00 PM | previous day |
| 3:00 PM | 2:00 AM | same day |
| 5:00 PM | 4:00 AM | same day |
| 6:00 PM | 5:00 AM | same day |
| 9:00 PM | 8:00 AM | same day |
Why people convert Istanbul to HST time
- Scheduling a call from Istanbul to HST: a 10:00 AM start in Istanbul lands at 9:00 PM in HST the previous day, so you can confirm the slot without doing the arithmetic yourself.
- Handling a -13h gap: Istanbul and HST 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 HST is 8:00 PM in Istanbul.
- Watching a live event or market open: Istanbul viewers need 8:00 PM in HST to catch a 9:00 AM start there, and 1:00 PM if the event is anchored to Istanbul.
- Always state the zone abbreviation, not just the hour. "3:00 PM TRT" 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 Istanbul takes the early slot, the next week HST does.
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.
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.
Best time to call between Istanbul and HST
With a -13h offset there is no overlap inside a normal 9 AM – 5 PM day. HST opens at 9:00 AM HST, which is 8:00 PM in Istanbul, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
Istanbul and HST have no shared working hours because of the -13h gap. Teams need to alternate early starts or rely on asynchronous handovers.
Istanbul is 13 hours behind HST (TRT UTC+03:00 → HST UTC-10:00). 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 Istanbul and HST?
Istanbul (TRT, UTC+03:00) is 13 hours behind HST (HST, UTC-10:00). The gap is currently -13h.
How do I convert Istanbul time to HST time?
Add -13h to Istanbul local time. For example, 9:00 AM in Istanbul is 8:00 PM in HST (previous day).
What time is it in HST right now?
HST uses HST at UTC-10:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -13h offset from Istanbul.
What is the best time to call HST from Istanbul?
There is no shared working-hours window because of the -13h gap. The closest option is 1:00 PM in Istanbul, which is 12:00 AM in HST.
Which is behind, Istanbul or HST?
Istanbul is 13 hours behind HST. When it is 12:00 PM in Istanbul it is 11:00 PM in HST.
Do Istanbul and HST use different time zones?
Istanbul (Turkey) uses TRT at UTC+03:00, while HST uses HST at UTC-10:00. The IANA identifiers are Europe/Istanbul and Pacific/Honolulu.
Does daylight saving time affect the Istanbul–HST difference?
Neither zone observes daylight saving time, so the -13h offset between Istanbul and HST is fixed all year.
Which other cities share Istanbul's time zone?
TRT also covers Istanbul, Ankara, Izmir, Bursa, Antalya.
Which countries use TRT, Istanbul's zone?
TRT is used in Turkey.
Is there a day difference between Istanbul and HST?
Sometimes. The -13h gap is large enough that 8:00 PM or later in Istanbul already falls on the in HST.
What is the time difference between Istanbul and HST?
HST is -13h from Istanbul.
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 timezone is HST in?
HST operates on its local timezone.
What are the business hours in Istanbul?
Standard business hours in Istanbul are 9:00 AM - 6:00 PM TRT.
Which countries use TRT (Turkey Time)?
TRT is used in Turkey.
Does TRT observe daylight saving time?
No, TRT does not observe daylight saving time and remains at UTC+03:00 year-round.
What are some interesting facts about TRT?
Turkey has used a permanent UTC+03:00 since September 2016. TRT is level with Moscow Standard Time and Arabia Standard Time all year.
Which cities are in the HST timezone?
Major cities in the HST timezone include Honolulu, Hilo, Kailua, Pearl City, Kapolei.
What is the UTC offset for HST?
Hawaii Standard Time (HST) is at UTC-10:00.
What should I know about the HST timezone?
Hawaii does not observe daylight saving time. HST is 5 hours behind EST in winter and 6 hours behind EDT in summer.
When is it midnight in Istanbul, what time is it in HST?
When it is 12:00 AM (midnight) in Istanbul (TRT), it is -13h later in HST (HST).
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