HKT to Tehran
-4h 30mHKT
HKTSOURCETehran
IRSTGreen rows indicate typical business hours (9 AM - 5 PM)
HKT and IRST on the World Map
The map below highlights the HKT (Hong Kong Time) and IRST (Iran Standard Time) timezone regions across the globe.
HKT – Hong Kong Time
UTC+08:00Hong Kong Time (HKT, UTC+08:00) is the time zone for Hong Kong, 8 hours ahead of UTC.
- •Hong Kong does not observe daylight saving time and has kept UTC+08:00 since 1979.
- •HKT shares its offset with China Standard Time, Singapore Time and Philippine Time.
- •The Hong Kong Stock Exchange opens at 09:30 HKT.
- •Hong Kong Time does not change with the seasons, so its gap to other zones is fixed.
IRST – Iran Standard Time
UTC+03:30Iran Standard Time (IRST) is the time zone for Iran, 3 hours and 30 minutes ahead of UTC.
- •IRST is one of only a few time zones with a 30-minute offset.
- •Iran observes daylight saving time, switching to IRDT (UTC+04:30).
- •Tehran has a metropolitan population of over 16 million.
About Tehran
WikipediaTehran operates on Iran Standard Time (IRST), UTC+3:30. Iran's unique half-hour offset makes Tehran time distinctive for regional business coordination.
Iran Standard Time (IRST) is one of few timezones with a 30-minute offset (UTC+3:30).
Everything You Need to Know About HKT and Tehran Time
HKT runs on Hong Kong Time (HKT) at UTC+08:00. Tehran runs on Iran Standard Time (IRST) at UTC+03:30. That puts HKT 4 hours 30 minutes behind Tehran — a difference of -4h 30m at the current offsets.
In practice, when it is 9:00 AM in HKT it is 4:30 AM in Tehran. Midnight in HKT is 7:30 PM in Tehran. Neither zone observes daylight saving time, so the offset between them stays constant all year.
HKT to Tehran time conversion table
| HKT (HKT) | Tehran (IRST) | Day |
|---|---|---|
| 12:00 AM | 7:30 PM | previous day |
| 6:00 AM | 1:30 AM | same day |
| 7:00 AM | 2:30 AM | same day |
| 8:00 AM | 3:30 AM | same day |
| 9:00 AM | 4:30 AM | same day |
| 12:00 PM | 7:30 AM | same day |
| 3:00 PM | 10:30 AM | same day |
| 5:00 PM | 12:30 PM | same day |
| 6:00 PM | 1:30 PM | same day |
| 9:00 PM | 4:30 PM | same day |
Why people convert HKT to Tehran time
- Scheduling a call from HKT to Tehran: a 10:00 AM start in HKT lands at 5:30 AM in Tehran, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both HKT and Tehran are inside the 9-to-5 working day between 1:30 PM and 5:00 PM HKT time (9:00 AM–12:30 PM IRST). That is roughly 3 hours 30 minutes of usable overlap.
- Watching a live event or market open: HKT viewers need 4:30 AM in Tehran to catch a 9:00 AM start there, and 4:30 AM if the event is anchored to HKT.
- Always state the zone abbreviation, not just the hour. "3:00 PM HKT" is unambiguous; "3 PM" across a -4h 30m gap is not.
- Block 1:30 PM–5:00 PM HKT as the recurring meeting window if you work primarily from HKT and need Tehran colleagues present.
About HKT (Hong Kong Time)
Hong Kong Time (HKT) is fixed at UTC+08:00 all year and does not observe daylight saving time. Hong Kong last used summer time in 1979 and has kept a single offset since. HKT shares the UTC+08:00 offset with China Standard Time, Singapore Time, Malaysian Time, Philippine Time and Australian Western Standard Time, but is listed separately because Hong Kong maintains its own timekeeping authority. As a major financial centre, Hong Kong's trading hours set the rhythm for markets across Asia, opening at 09:30 HKT which is 01:30 in London and 20:30 the previous evening in New York.
About IRST (Iran Standard Time)
Iran Standard Time (IRST) is one of the few time zones with a 30-minute offset. Iran observes daylight saving time (IRDT, UTC+04:30) from late March to late September. Tehran, the capital, is one of the largest cities in the Middle East.
Best time to call between HKT and Tehran
Both HKT and Tehran sit inside the 9 AM – 5 PM working day between 1:30 PM–5:00 PM HKT, which is 9:00 AM–12:30 PM IRST. That gives roughly 3 hours and 30 minutes of shared time — the safest window for a live call or meeting.
Business hours overlap
HKT and Tehran overlap for about 3 hours during the working day — enough for meetings if you avoid the edges of the window.
HKT is 4 hours 30 minutes behind Tehran (HKT UTC+08:00 → IRST UTC+03:30). The shared working window is 1:30 PM–5:00 PM HKT. 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 HKT and Tehran?
HKT (HKT, UTC+08:00) is 4 hours 30 minutes behind Tehran (IRST, UTC+03:30). The gap is currently -4h 30m.
How do I convert HKT time to Tehran time?
Add -4h 30m to HKT local time. For example, 9:00 AM in HKT is 4:30 AM in Tehran.
What time is it in Tehran right now?
Tehran uses IRST at UTC+03:30. Use the live converter at the top of this page — it updates in real time and already accounts for the -4h 30m offset from HKT.
What is the best time to call Tehran from HKT?
Call between 1:30 PM and 5:00 PM HKT — that maps to 9:00 AM–12:30 PM IRST and keeps both parties inside the working day.
Which is behind, HKT or Tehran?
HKT is 4 hours 30 minutes behind Tehran. When it is 12:00 PM in HKT it is 7:30 AM in Tehran.
Do HKT and Tehran use different time zones?
HKT uses HKT at UTC+08:00, while Tehran (Iran) uses IRST at UTC+03:30. The IANA identifiers are Asia/Hong_Kong and Asia/Tehran.
Does daylight saving time affect the HKT–Tehran difference?
Neither zone observes daylight saving time, so the -4h 30m offset between HKT and Tehran is fixed all year.
Which other cities share HKT's time zone?
HKT also covers Hong Kong, Kowloon, Tsuen Wan, Sha Tin.
Which countries use HKT, HKT's zone?
HKT is used in Hong Kong SAR.
Is there a day difference between HKT and Tehran?
Not normally. The -4h 30m gap only pushes the date over the previous day.
What is the time difference between HKT and Tehran?
Tehran is -4h 30m from HKT.
What timezone is HKT in?
HKT operates on its local timezone.
What timezone is Tehran in?
Tehran operates on Iran Standard Time (IRST), UTC+3:30. Iran's unique half-hour offset makes Tehran time distinctive for regional business coordination.
What are the business hours in Tehran?
Standard business hours in Tehran are 8:00 AM - 4:00 PM IRST.
Which countries use HKT (Hong Kong Time)?
HKT is used in Hong Kong SAR.
Does HKT observe daylight saving time?
No, HKT does not observe daylight saving time and remains at UTC+08:00 year-round.
What are some interesting facts about HKT?
Hong Kong does not observe daylight saving time and has kept UTC+08:00 since 1979. HKT shares its offset with China Standard Time, Singapore Time and Philippine Time.
Which cities are in the IRST timezone?
Major cities in the IRST timezone include Tehran, Isfahan, Mashhad, Tabriz, Shiraz, Karaj.
What is the UTC offset for IRST?
Iran Standard Time (IRST) is at UTC+03:30. During daylight saving time, it shifts to IRDT.
What should I know about the IRST timezone?
IRST is one of only a few time zones with a 30-minute offset. Iran observes daylight saving time, switching to IRDT (UTC+04:30).
When is it midnight in HKT, what time is it in Tehran?
When it is 12:00 AM (midnight) in HKT (HKT), it is -4h 30m later in Tehran (IRST).
Related Developer Tools
Explore more tools that work great with timezone conversions for international teams:
Related Timezone Conversions
More HKT time conversions
- hkt to hong kong
- hkt to new york
- hkt to london
- hkt to dubai
- hkt to tokyo
- hkt to singapore
- hkt to sydney
- hkt to los angeles
- hkt to paris
- hkt to delhi
- hkt to mumbai
- hkt to berlin
- hkt to toronto
- hkt to kathmandu
- new york to hkt
- london to hkt
- dubai to hkt
- tokyo to hkt
- singapore to hkt
- sydney to hkt
- los angeles to hkt
- paris to hkt
- delhi to hkt
- mumbai to hkt
- berlin to hkt
- hong kong to hkt
- toronto to hkt
- kathmandu to hkt
See every conversion from HKT →·See every conversion from Tehran →