IST to Vietnam
+1h 30mIST
ISTSOURCEVietnam
ICTGreen rows indicate typical business hours (9 AM - 5 PM)
IST and ICT on the World Map
The map below highlights the IST (India Standard Time) and ICT (Indochina Time) timezone regions across the globe.
IST – India Standard Time
UTC+05:30India Standard Time (IST) is the time zone for India and Sri Lanka, 5 hours and 30 minutes ahead of UTC.
- •India is 10 hours 30 minutes ahead of EST and 5 hours 30 minutes ahead of GMT.
- •India uses a single time zone despite spanning 30° of longitude.
- •IST is one of only a handful of time zones with a 30-minute offset.
- •IST is the most populous single time zone in the world with over 1.4 billion people.
- •The Bombay Stock Exchange (BSE) and National Stock Exchange (NSE) operate on IST.
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.
IST vs Vietnam: Offsets, DST and Best Call Times
IST runs on India Standard Time (IST) at UTC+05:30. Vietnam runs on Indochina Time (ICT) at UTC+07:00. That puts IST 1 hour 30 minutes ahead of Vietnam — a difference of +1h 30m at the current offsets.
In practice, when it is 9:00 AM in IST it is 10:30 AM in Vietnam. Midnight in IST is 1:30 AM in Vietnam. Neither zone observes daylight saving time, so the offset between them stays constant all year.
IST to Vietnam time conversion table
| IST (IST) | Vietnam (ICT) | Day |
|---|---|---|
| 12:00 AM | 1:30 AM | same day |
| 6:00 AM | 7:30 AM | same day |
| 7:00 AM | 8:30 AM | same day |
| 8:00 AM | 9:30 AM | same day |
| 9:00 AM | 10:30 AM | same day |
| 12:00 PM | 1:30 PM | same day |
| 3:00 PM | 4:30 PM | same day |
| 5:00 PM | 6:30 PM | same day |
| 6:00 PM | 7:30 PM | same day |
| 9:00 PM | 10:30 PM | same day |
Why people convert IST to Vietnam time
- Scheduling a call from IST to Vietnam: a 10:00 AM start in IST lands at 11:30 AM in Vietnam, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both IST and Vietnam are inside the 9-to-5 working day between 9:00 AM and 3:30 PM IST time (10:30 AM–5:00 PM ICT). That is roughly 6 hours 30 minutes of usable overlap.
- Coordinating a IST-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 IST" is unambiguous; "3 PM" across a +1h 30m gap is not.
- Block 9:00 AM–3:30 PM IST as the recurring meeting window if you work primarily from IST and need Vietnam colleagues present.
About IST (India Standard Time)
India Standard Time (IST) is the time observed throughout India and Sri Lanka. It is based on the 82.5°E meridian, passing through Mirzapur in Uttar Pradesh. India uses a single time zone despite spanning roughly 30° of longitude, which has been debated. IST does not observe daylight saving time. India is the world's most populous country, making IST one of the most-used time zones globally. The IT outsourcing industry and call centers operate primarily on IST, making the EST-to-IST conversion one of the most searched timezone conversions.
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 IST and Vietnam
Both IST and Vietnam sit inside the 9 AM – 5 PM working day between 9:00 AM–3:30 PM IST, which is 10:30 AM–5:00 PM ICT. That gives roughly 6 hours and 30 minutes of shared time — the safest window for a live call or meeting.
Business hours overlap
IST and Vietnam share 6 hours of working-hours overlap (9:00 AM–3:30 PM IST), so scheduling a live meeting is straightforward.
IST is 1 hour 30 minutes ahead of Vietnam (IST UTC+05:30 → ICT UTC+07:00). The shared working window is 9:00 AM–3:30 PM IST. 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 IST and Vietnam?
IST (IST, UTC+05:30) is 1 hour 30 minutes ahead of Vietnam (ICT, UTC+07:00). The gap is currently +1h 30m.
How do I convert IST time to Vietnam time?
Add +1h 30m to IST local time. For example, 9:00 AM in IST is 10:30 AM 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 +1h 30m offset from IST.
What is the best time to call Vietnam from IST?
Call between 9:00 AM and 3:30 PM IST — that maps to 10:30 AM–5:00 PM ICT and keeps both parties inside the working day.
Which is ahead, IST or Vietnam?
IST is 1 hour 30 minutes ahead of Vietnam. When it is 12:00 PM in IST it is 1:30 PM in Vietnam.
Do IST and Vietnam use different time zones?
IST uses IST at UTC+05:30, while Vietnam (Vietnam) uses ICT at UTC+07:00. The IANA identifiers are Asia/Kolkata and Asia/Ho_Chi_Minh.
Does daylight saving time affect the IST–Vietnam difference?
Neither zone observes daylight saving time, so the +1h 30m offset between IST and Vietnam is fixed all year.
Which other cities share IST's time zone?
IST also covers Mumbai, Delhi, Bangalore, Kolkata, Chennai, Hyderabad, Pune, Ahmedabad and 4 more.
Which countries use IST, IST's zone?
IST is used in India, Sri Lanka.
Is there a day difference between IST and Vietnam?
Not normally. The +1h 30m gap only pushes the date over for late-evening times.
What is the time difference between IST and Vietnam?
Vietnam is +1h 30m from IST.
What timezone is IST in?
IST operates on its local timezone.
What timezone is Vietnam in?
Vietnam operates on its local timezone.
Which countries use IST (India Standard Time)?
IST is used in India, Sri Lanka.
Does IST observe daylight saving time?
No, IST does not observe daylight saving time and remains at UTC+05:30 year-round.
What are some interesting facts about IST?
India is 10 hours 30 minutes ahead of EST and 5 hours 30 minutes ahead of GMT. India uses a single time zone despite spanning 30° of longitude.
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 IST, what time is it in Vietnam?
When it is 12:00 AM (midnight) in IST (IST), it is +1h 30m later in Vietnam (ICT).
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