Colombo to CAT
-3h 30mColombo
ISTSOURCECAT
CATGreen rows indicate typical business hours (9 AM - 5 PM)
IST and CAT on the World Map
The map below highlights the IST (India Standard Time) and CAT (Central Africa 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.
CAT – Central Africa Time
UTC+02:00Central Africa Time (CAT, UTC+02:00) covers Zimbabwe, Zambia, Mozambique, Malawi and neighbouring countries.
- •Central Africa Time is fixed at UTC+02:00 with no daylight saving.
- •CAT matches South Africa Standard Time (SAST) all year.
- •It is the same offset as Central European Time in winter.
- •Harare is level with Johannesburg and one hour ahead of Lagos.
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 CAT
Colombo runs on India Standard Time (IST) at UTC+05:30. CAT runs on Central Africa Time (CAT) at UTC+02:00. That puts Colombo 3 hours 30 minutes behind CAT — a difference of -3h 30m at the current offsets.
In practice, when it is 9:00 AM in Colombo it is 5:30 AM in CAT. Midnight in Colombo is 8:30 PM in CAT. Neither zone observes daylight saving time, so the offset between them stays constant all year.
Colombo to CAT time conversion table
| Colombo (IST) | CAT (CAT) | Day |
|---|---|---|
| 12:00 AM | 8:30 PM | previous day |
| 6:00 AM | 2:30 AM | same day |
| 7:00 AM | 3:30 AM | same day |
| 8:00 AM | 4:30 AM | same day |
| 9:00 AM | 5:30 AM | same day |
| 12:00 PM | 8:30 AM | same day |
| 3:00 PM | 11:30 AM | same day |
| 5:00 PM | 1:30 PM | same day |
| 6:00 PM | 2:30 PM | same day |
| 9:00 PM | 5:30 PM | same day |
Why people convert Colombo to CAT time
- Scheduling a call from Colombo to CAT: a 10:00 AM start in Colombo lands at 6:30 AM in CAT, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both Colombo and CAT are inside the 9-to-5 working day between 12:30 PM and 5:00 PM IST time (9:00 AM–1:30 PM CAT). That is roughly 4 hours 30 minutes of usable overlap.
- Coordinating a Colombo-based team with CAT 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 -3h 30m gap is not.
- Block 12:30 PM–5:00 PM IST as the recurring meeting window if you work primarily from Colombo and need CAT 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 CAT (Central Africa Time)
Central Africa Time (CAT) is fixed at UTC+02:00 all year across a broad belt of southern and central Africa, including Zimbabwe, Zambia, Mozambique, Malawi, Rwanda, Burundi and the eastern Democratic Republic of the Congo. None of these countries observes daylight saving time, so CAT never shifts. It is the same offset as South Africa Standard Time (SAST) and the winter version of Central European Time, which makes CAT a convenient bridge between African, European and Middle Eastern schedules — Harare is level with Johannesburg all year and one hour ahead of Lagos.
Best time to call between Colombo and CAT
Both Colombo and CAT sit inside the 9 AM – 5 PM working day between 12:30 PM–5:00 PM IST, which is 9:00 AM–1:30 PM CAT. That gives roughly 4 hours and 30 minutes of shared time — the safest window for a live call or meeting.
Business hours overlap
Colombo and CAT overlap for about 4 hours during the working day — enough for meetings if you avoid the edges of the window.
Colombo is 3 hours 30 minutes behind CAT (IST UTC+05:30 → CAT UTC+02:00). The shared working window is 12:30 PM–5:00 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 CAT?
Colombo (IST, UTC+05:30) is 3 hours 30 minutes behind CAT (CAT, UTC+02:00). The gap is currently -3h 30m.
How do I convert Colombo time to CAT time?
Add -3h 30m to Colombo local time. For example, 9:00 AM in Colombo is 5:30 AM in CAT.
What time is it in CAT right now?
CAT uses CAT at UTC+02:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -3h 30m offset from Colombo.
What is the best time to call CAT from Colombo?
Call between 12:30 PM and 5:00 PM IST — that maps to 9:00 AM–1:30 PM CAT and keeps both parties inside the working day.
Which is behind, Colombo or CAT?
Colombo is 3 hours 30 minutes behind CAT. When it is 12:00 PM in Colombo it is 8:30 AM in CAT.
Do Colombo and CAT use different time zones?
Colombo (Sri Lanka) uses IST at UTC+05:30, while CAT uses CAT at UTC+02:00. The IANA identifiers are Asia/Colombo and Africa/Harare.
Does daylight saving time affect the Colombo–CAT difference?
Neither zone observes daylight saving time, so the -3h 30m offset between Colombo and CAT 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 CAT?
Not normally. The -3h 30m gap only pushes the date over the previous day.
What is the time difference between Colombo and CAT?
CAT is -3h 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 CAT in?
CAT 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 CAT timezone?
Major cities in the CAT timezone include Harare, Lusaka, Maputo, Lilongwe, Kigali.
What is the UTC offset for CAT?
Central Africa Time (CAT) is at UTC+02:00.
What should I know about the CAT timezone?
Central Africa Time is fixed at UTC+02:00 with no daylight saving. CAT matches South Africa Standard Time (SAST) all year.
When is it midnight in Colombo, what time is it in CAT?
When it is 12:00 AM (midnight) in Colombo (IST), it is -3h 30m later in CAT (CAT).
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