ICT to Colombo
-1h 30mICT
ICTSOURCEColombo
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.
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.
Everything You Need to Know About ICT and Colombo Time
ICT runs on Indochina Time (ICT) at UTC+07:00. Colombo runs on India Standard Time (IST) at UTC+05:30. That puts ICT 1 hour 30 minutes behind Colombo — a difference of -1h 30m at the current offsets.
In practice, when it is 9:00 AM in ICT it is 7:30 AM in Colombo. Midnight in ICT is 10:30 PM in Colombo. Neither zone observes daylight saving time, so the offset between them stays constant all year.
ICT to Colombo time conversion table
| ICT (ICT) | Colombo (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 ICT to Colombo time
- Scheduling a call from ICT to Colombo: a 10:00 AM start in ICT lands at 8:30 AM in Colombo, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both ICT and Colombo 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.
- Watching a live event or market open: ICT viewers need 7:30 AM in Colombo to catch a 9:00 AM start there, and 1:30 AM if the event is anchored to ICT.
- 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 ICT and need Colombo 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 ICT and Colombo
Both ICT and Colombo 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
ICT and Colombo share 6 hours of working-hours overlap (10:30 AM–5:00 PM ICT), so scheduling a live meeting is straightforward.
ICT is 1 hour 30 minutes behind Colombo (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 ICT and Colombo?
ICT (ICT, UTC+07:00) is 1 hour 30 minutes behind Colombo (IST, UTC+05:30). The gap is currently -1h 30m.
How do I convert ICT time to Colombo time?
Add -1h 30m to ICT local time. For example, 9:00 AM in ICT is 7:30 AM in Colombo.
What time is it in Colombo right now?
Colombo 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 ICT.
What is the best time to call Colombo from ICT?
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, ICT or Colombo?
ICT is 1 hour 30 minutes behind Colombo. When it is 12:00 PM in ICT it is 10:30 AM in Colombo.
Do ICT and Colombo use different time zones?
ICT uses ICT at UTC+07:00, while Colombo (Sri Lanka) uses IST at UTC+05:30. The IANA identifiers are Asia/Bangkok and Asia/Colombo.
Does daylight saving time affect the ICT–Colombo difference?
Neither zone observes daylight saving time, so the -1h 30m offset between ICT and Colombo is fixed all year.
Which other cities share ICT's time zone?
ICT also covers Bangkok, Ho Chi Minh City, Hanoi, Jakarta, Phnom Penh, Vientiane.
Which countries use ICT, ICT's zone?
ICT is used in Thailand, Vietnam, Cambodia, Laos, Indonesia (WIB).
Is there a day difference between ICT and Colombo?
Not normally. The -1h 30m gap only pushes the date over the previous day.
What is the time difference between ICT and Colombo?
Colombo is -1h 30m from ICT.
What timezone is ICT in?
ICT operates on its local timezone.
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 are the business hours in Colombo?
Standard business hours in Colombo are 9:00 AM - 5:00 PM IST.
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 ICT, what time is it in Colombo?
When it is 12:00 AM (midnight) in ICT (ICT), it is -1h 30m later in Colombo (IST).
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