Tehran to Vietnam
+3h 30mTehran
IRSTSOURCEVietnam
ICTGreen rows indicate typical business hours (9 AM - 5 PM)
IRST and ICT on the World Map
The map below highlights the IRST (Iran Standard Time) and ICT (Indochina Time) timezone regions across the globe.
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.
ICT – Indochina Time
UTC+07:00Indochina Time (ICT) is the time zone for Vietnam, Thailand, Laos, and Cambodia, 7 hours ahead of UTC.
- •Bangkok is one of the most visited cities in the world.
- •ICT is 12 hours ahead of EST.
- •Thailand, Vietnam, and Cambodia all share ICT.
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).
Tehran vs Vietnam: Offsets, DST and Best Call Times
Tehran runs on Iran Standard Time (IRST) at UTC+03:30. Vietnam runs on Indochina Time (ICT) at UTC+07:00. That puts Tehran 3 hours 30 minutes ahead of Vietnam — a difference of +3h 30m at the current offsets.
In practice, when it is 9:00 AM in Tehran it is 12:30 PM in Vietnam. Midnight in Tehran is 3:30 AM in Vietnam. Neither zone observes daylight saving time, so the offset between them stays constant all year.
Tehran to Vietnam time conversion table
| Tehran (IRST) | Vietnam (ICT) | Day |
|---|---|---|
| 12:00 AM | 3:30 AM | same day |
| 6:00 AM | 9:30 AM | same day |
| 7:00 AM | 10:30 AM | same day |
| 8:00 AM | 11:30 AM | same day |
| 9:00 AM | 12:30 PM | same day |
| 12:00 PM | 3:30 PM | same day |
| 3:00 PM | 6:30 PM | same day |
| 5:00 PM | 8:30 PM | same day |
| 6:00 PM | 9:30 PM | same day |
| 9:00 PM | 12:30 AM | next day |
Why people convert Tehran to Vietnam time
- Scheduling a call from Tehran to Vietnam: a 10:00 AM start in Tehran lands at 1:30 PM in Vietnam, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both Tehran and Vietnam are inside the 9-to-5 working day between 9:00 AM and 1:30 PM IRST time (12:30 PM–5:00 PM ICT). That is roughly 4 hours 30 minutes of usable overlap.
- Coordinating a Tehran-based team with Vietnam contacts: quoting times in the other side's local clock — not your own — removes the single biggest source of missed meetings.
- Always state the zone abbreviation, not just the hour. "3:00 PM IRST" is unambiguous; "3 PM" across a +3h 30m gap is not.
- Block 9:00 AM–1:30 PM IRST as the recurring meeting window if you work primarily from Tehran and need Vietnam colleagues present.
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.
About ICT (Indochina Time)
Indochina Time (ICT) is used across Southeast Asia including Vietnam, Thailand, Laos, and Cambodia. Indonesia (Western time, WIB) also uses UTC+07:00. ICT does not observe daylight saving time.
Best time to call between Tehran and Vietnam
Both Tehran and Vietnam sit inside the 9 AM – 5 PM working day between 9:00 AM–1:30 PM IRST, which is 12:30 PM–5:00 PM ICT. That gives roughly 4 hours and 30 minutes of shared time — the safest window for a live call or meeting.
Business hours overlap
Tehran and Vietnam overlap for about 4 hours during the working day — enough for meetings if you avoid the edges of the window.
Tehran is 3 hours 30 minutes ahead of Vietnam (IRST UTC+03:30 → ICT UTC+07:00). The shared working window is 9:00 AM–1:30 PM IRST. 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 Tehran and Vietnam?
Tehran (IRST, UTC+03:30) is 3 hours 30 minutes ahead of Vietnam (ICT, UTC+07:00). The gap is currently +3h 30m.
How do I convert Tehran time to Vietnam time?
Add +3h 30m to Tehran local time. For example, 9:00 AM in Tehran is 12:30 PM in Vietnam.
What time is it in Vietnam right now?
Vietnam uses ICT at UTC+07:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +3h 30m offset from Tehran.
What is the best time to call Vietnam from Tehran?
Call between 9:00 AM and 1:30 PM IRST — that maps to 12:30 PM–5:00 PM ICT and keeps both parties inside the working day.
Which is ahead, Tehran or Vietnam?
Tehran is 3 hours 30 minutes ahead of Vietnam. When it is 12:00 PM in Tehran it is 3:30 PM in Vietnam.
Do Tehran and Vietnam use different time zones?
Tehran (Iran) uses IRST at UTC+03:30, while Vietnam (Vietnam) uses ICT at UTC+07:00. The IANA identifiers are Asia/Tehran and Asia/Ho_Chi_Minh.
Does daylight saving time affect the Tehran–Vietnam difference?
Neither zone observes daylight saving time, so the +3h 30m offset between Tehran and Vietnam is fixed all year.
Which other cities share Tehran's time zone?
IRST also covers Tehran, Isfahan, Mashhad, Tabriz, Shiraz, Karaj.
Which countries use IRST, Tehran's zone?
IRST is used in Iran.
Is there a day difference between Tehran and Vietnam?
Not normally. The +3h 30m gap only pushes the date over for late-evening times.
What is the time difference between Tehran and Vietnam?
Vietnam is +3h 30m from Tehran.
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 timezone is Vietnam in?
Vietnam operates on its local timezone.
What are the business hours in Tehran?
Standard business hours in Tehran are 8:00 AM - 4:00 PM IRST.
Which countries use IRST (Iran Standard Time)?
IRST is used in Iran.
Does IRST observe daylight saving time?
Yes, IRST switches to IRDT during summer months.
What are some interesting facts about IRST?
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).
Which cities are in the ICT timezone?
Major cities in the ICT timezone include Bangkok, Ho Chi Minh City, Hanoi, Jakarta, Phnom Penh, Vientiane.
What is the UTC offset for ICT?
Indochina Time (ICT) is at UTC+07:00.
What should I know about the ICT timezone?
Bangkok is one of the most visited cities in the world. ICT is 12 hours ahead of EST.
When is it midnight in Tehran, what time is it in Vietnam?
When it is 12:00 AM (midnight) in Tehran (IRST), it is +3h 30m later in Vietnam (ICT).
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