Colombo to ICT
+1h 30mColombo
ISTSOURCEICT
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.
About Colombo
WikipediaColombo operates on Sri Lanka Time (SLST), UTC+5:30. Sharing India's timezone, Colombo is a key South Asian trade and tourism hub.
Sri Lanka Standard Time (SLST) uses UTC+5:30, same offset as India.
Comparing Time Zones: Colombo and ICT
Colombo runs on India Standard Time (IST) at UTC+05:30. ICT runs on Indochina Time (ICT) at UTC+07:00. That puts Colombo 1 hour 30 minutes ahead of ICT — a difference of +1h 30m at the current offsets.
In practice, when it is 9:00 AM in Colombo it is 10:30 AM in ICT. Midnight in Colombo is 1:30 AM in ICT. Neither zone observes daylight saving time, so the offset between them stays constant all year.
Colombo to ICT time conversion table
| Colombo (IST) | ICT (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 Colombo to ICT time
- Scheduling a call from Colombo to ICT: a 10:00 AM start in Colombo lands at 11:30 AM in ICT, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both Colombo and ICT 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.
- Keeping family and friends in sync: knowing that 8:00 PM in Colombo is 9:30 PM in ICT makes it easy to avoid calling at 3 AM.
- 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 Colombo and need ICT 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 Colombo and ICT
Both Colombo and ICT 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
Colombo and ICT share 6 hours of working-hours overlap (9:00 AM–3:30 PM IST), so scheduling a live meeting is straightforward.
Colombo is 1 hour 30 minutes ahead of ICT (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 Colombo and ICT?
Colombo (IST, UTC+05:30) is 1 hour 30 minutes ahead of ICT (ICT, UTC+07:00). The gap is currently +1h 30m.
How do I convert Colombo time to ICT time?
Add +1h 30m to Colombo local time. For example, 9:00 AM in Colombo is 10:30 AM in ICT.
What time is it in ICT right now?
ICT 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 Colombo.
What is the best time to call ICT from Colombo?
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, Colombo or ICT?
Colombo is 1 hour 30 minutes ahead of ICT. When it is 12:00 PM in Colombo it is 1:30 PM in ICT.
Do Colombo and ICT use different time zones?
Colombo (Sri Lanka) uses IST at UTC+05:30, while ICT uses ICT at UTC+07:00. The IANA identifiers are Asia/Colombo and Asia/Bangkok.
Does daylight saving time affect the Colombo–ICT difference?
Neither zone observes daylight saving time, so the +1h 30m offset between Colombo and ICT is fixed all year.
Which other cities share Colombo's time zone?
IST also covers Mumbai, Delhi, Bangalore, Kolkata, Chennai, Hyderabad, Pune, Ahmedabad and 4 more.
Which countries use IST, Colombo's zone?
IST is used in India, Sri Lanka.
Is there a day difference between Colombo and ICT?
Not normally. The +1h 30m gap only pushes the date over for late-evening times.
What is the time difference between Colombo and ICT?
ICT is +1h 30m from Colombo.
What timezone is Colombo in?
Colombo operates on Sri Lanka Time (SLST), UTC+5:30. Sharing India's timezone, Colombo is a key South Asian trade and tourism hub.
What timezone is ICT in?
ICT operates on its local timezone.
What are the business hours in Colombo?
Standard business hours in Colombo are 9:00 AM - 5:00 PM IST.
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 Colombo, what time is it in ICT?
When it is 12:00 AM (midnight) in Colombo (IST), it is +1h 30m later in ICT (ICT).
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