Vietnam to Sri Lanka
-1h 30mVietnam
ICTSOURCESri Lanka
ISTGreen rows indicate typical business hours (9 AM - 5 PM)
ICT and IST on the World Map
The map below highlights the ICT (Indochina Time) and IST (India Standard Time) timezone regions across the globe.
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 – 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.
Understanding the -1h 30m Gap: Vietnam vs Sri Lanka
Vietnam runs on Indochina Time (ICT) at UTC+07:00. Sri Lanka runs on India Standard Time (IST) at UTC+05:30. That puts Vietnam 1 hour 30 minutes behind Sri Lanka — a difference of -1h 30m at the current offsets.
In practice, when it is 9:00 AM in Vietnam it is 7:30 AM in Sri Lanka. Midnight in Vietnam is 10:30 PM in Sri Lanka. Neither zone observes daylight saving time, so the offset between them stays constant all year.
Vietnam to Sri Lanka time conversion table
| Vietnam (ICT) | Sri Lanka (IST) | Day |
|---|---|---|
| 12:00 AM | 10:30 PM | previous day |
| 6:00 AM | 4:30 AM | same day |
| 7:00 AM | 5:30 AM | same day |
| 8:00 AM | 6:30 AM | same day |
| 9:00 AM | 7:30 AM | same day |
| 12:00 PM | 10:30 AM | same day |
| 3:00 PM | 1:30 PM | same day |
| 5:00 PM | 3:30 PM | same day |
| 6:00 PM | 4:30 PM | same day |
| 9:00 PM | 7:30 PM | same day |
Why people convert Vietnam to Sri Lanka time
- Scheduling a call from Vietnam to Sri Lanka: a 10:00 AM start in Vietnam lands at 8:30 AM in Sri Lanka, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both Vietnam and Sri Lanka are inside the 9-to-5 working day between 10:30 AM and 5:00 PM ICT time (9:00 AM–3:30 PM IST). That is roughly 6 hours 30 minutes of usable overlap.
- Keeping family and friends in sync: knowing that 8:00 PM in Vietnam is 6:30 PM in Sri Lanka makes it easy to avoid calling at 3 AM.
- Always state the zone abbreviation, not just the hour. "3:00 PM ICT" is unambiguous; "3 PM" across a -1h 30m gap is not.
- Block 10:30 AM–5:00 PM ICT as the recurring meeting window if you work primarily from Vietnam and need Sri Lanka colleagues present.
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.
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.
Best time to call between Vietnam and Sri Lanka
Both Vietnam and Sri Lanka sit inside the 9 AM – 5 PM working day between 10:30 AM–5:00 PM ICT, which is 9:00 AM–3:30 PM IST. That gives roughly 6 hours and 30 minutes of shared time — the safest window for a live call or meeting.
Business hours overlap
Vietnam and Sri Lanka share 6 hours of working-hours overlap (10:30 AM–5:00 PM ICT), so scheduling a live meeting is straightforward.
Vietnam is 1 hour 30 minutes behind Sri Lanka (ICT UTC+07:00 → IST UTC+05:30). The shared working window is 10:30 AM–5:00 PM ICT. 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 Vietnam and Sri Lanka?
Vietnam (ICT, UTC+07:00) is 1 hour 30 minutes behind Sri Lanka (IST, UTC+05:30). The gap is currently -1h 30m.
How do I convert Vietnam time to Sri Lanka time?
Add -1h 30m to Vietnam local time. For example, 9:00 AM in Vietnam is 7:30 AM in Sri Lanka.
What time is it in Sri Lanka right now?
Sri Lanka uses IST at UTC+05:30. Use the live converter at the top of this page — it updates in real time and already accounts for the -1h 30m offset from Vietnam.
What is the best time to call Sri Lanka from Vietnam?
Call between 10:30 AM and 5:00 PM ICT — that maps to 9:00 AM–3:30 PM IST and keeps both parties inside the working day.
Which is behind, Vietnam or Sri Lanka?
Vietnam is 1 hour 30 minutes behind Sri Lanka. When it is 12:00 PM in Vietnam it is 10:30 AM in Sri Lanka.
Do Vietnam and Sri Lanka use different time zones?
Vietnam (Vietnam) uses ICT at UTC+07:00, while Sri Lanka (Sri Lanka) uses IST at UTC+05:30. The IANA identifiers are Asia/Ho_Chi_Minh and Asia/Colombo.
Does daylight saving time affect the Vietnam–Sri Lanka difference?
Neither zone observes daylight saving time, so the -1h 30m offset between Vietnam and Sri Lanka is fixed all year.
Which other cities share Vietnam's time zone?
ICT also covers Bangkok, Ho Chi Minh City, Hanoi, Jakarta, Phnom Penh, Vientiane.
Which countries use ICT, Vietnam's zone?
ICT is used in Thailand, Vietnam, Cambodia, Laos, Indonesia (WIB).
Is there a day difference between Vietnam and Sri Lanka?
Not normally. The -1h 30m gap only pushes the date over the previous day.
What is the time difference between Vietnam and Sri Lanka?
Sri Lanka is -1h 30m from Vietnam.
What timezone is Vietnam in?
Vietnam operates on its local timezone.
What timezone is Sri Lanka in?
Sri Lanka operates on its local timezone.
Which countries use ICT (Indochina Time)?
ICT is used in Thailand, Vietnam, Cambodia, Laos, Indonesia (WIB).
Does ICT observe daylight saving time?
No, ICT does not observe daylight saving time and remains at UTC+07:00 year-round.
What are some interesting facts about ICT?
Bangkok is one of the most visited cities in the world. ICT is 12 hours ahead of EST.
Which cities are in the IST timezone?
Major cities in the IST timezone include Mumbai, Delhi, Bangalore, Kolkata, Chennai, Hyderabad, Pune, Ahmedabad.
What is the UTC offset for IST?
India Standard Time (IST) is at UTC+05:30.
What should I know about the IST timezone?
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.
When is it midnight in Vietnam, what time is it in Sri Lanka?
When it is 12:00 AM (midnight) in Vietnam (ICT), it is -1h 30m later in Sri Lanka (IST).
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