Colombo to Japan
+3h 30mColombo
ISTSOURCEJapan
JSTGreen rows indicate typical business hours (9 AM - 5 PM)
IST and JST on the World Map
The map below highlights the IST (India Standard Time) and JST (Japan Standard 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.
JST – Japan Standard Time
UTC+09:00Japan Standard Time (JST) is the time zone for Japan, 9 hours ahead of UTC.
- •Japan does not observe daylight saving time.
- •Tokyo is the most populous metropolitan area in the world.
- •The Tokyo Stock Exchange operates from 9:00 AM to 3:00 PM JST.
- •JST is 14 hours ahead of EST and 9 hours ahead of GMT.
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 Colombo and Japan Time
Colombo runs on India Standard Time (IST) at UTC+05:30. Japan runs on Japan Standard Time (JST) at UTC+09:00. That puts Colombo 3 hours 30 minutes ahead of Japan — a difference of +3h 30m at the current offsets.
In practice, when it is 9:00 AM in Colombo it is 12:30 PM in Japan. Midnight in Colombo is 3:30 AM in Japan. Neither zone observes daylight saving time, so the offset between them stays constant all year.
Colombo to Japan time conversion table
| Colombo (IST) | Japan (JST) | Day |
|---|---|---|
| 12:00 AM | 3:30 AM | same day |
| 6:00 AM | 9:30 AM | same day |
| 7:00 AM | 10:30 AM | same day |
| 8:00 AM | 11:30 AM | same day |
| 9:00 AM | 12:30 PM | same day |
| 12:00 PM | 3:30 PM | same day |
| 3:00 PM | 6:30 PM | same day |
| 5:00 PM | 8:30 PM | same day |
| 6:00 PM | 9:30 PM | same day |
| 9:00 PM | 12:30 AM | next day |
Why people convert Colombo to Japan time
- Scheduling a call from Colombo to Japan: a 10:00 AM start in Colombo lands at 1:30 PM in Japan, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both Colombo and Japan are inside the 9-to-5 working day between 9:00 AM and 1:30 PM IST time (12:30 PM–5:00 PM JST). That is roughly 4 hours 30 minutes of usable overlap.
- Booking travel or deliveries: tracking Japan local time against Colombo keeps pickup windows and arrival estimates honest across the +3h 30m offset.
- 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 9:00 AM–1:30 PM IST as the recurring meeting window if you work primarily from Colombo and need Japan 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 JST (Japan Standard Time)
Japan Standard Time (JST) is the standard time zone for all of Japan. Japan does not observe daylight saving time. JST is 9 hours ahead of UTC and 14 hours ahead of EST. The Tokyo Stock Exchange, the world's third largest by market capitalization, operates on JST. South Korea uses the same offset (KST) but it is a distinct time zone.
Best time to call between Colombo and Japan
Both Colombo and Japan sit inside the 9 AM – 5 PM working day between 9:00 AM–1:30 PM IST, which is 12:30 PM–5:00 PM JST. 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 Japan 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 ahead of Japan (IST UTC+05:30 → JST UTC+09:00). The shared working window is 9:00 AM–1:30 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 Japan?
Colombo (IST, UTC+05:30) is 3 hours 30 minutes ahead of Japan (JST, UTC+09:00). The gap is currently +3h 30m.
How do I convert Colombo time to Japan time?
Add +3h 30m to Colombo local time. For example, 9:00 AM in Colombo is 12:30 PM in Japan.
What time is it in Japan right now?
Japan uses JST at UTC+09:00. 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 Japan from Colombo?
Call between 9:00 AM and 1:30 PM IST — that maps to 12:30 PM–5:00 PM JST and keeps both parties inside the working day.
Which is ahead, Colombo or Japan?
Colombo is 3 hours 30 minutes ahead of Japan. When it is 12:00 PM in Colombo it is 3:30 PM in Japan.
Do Colombo and Japan use different time zones?
Colombo (Sri Lanka) uses IST at UTC+05:30, while Japan (Japan) uses JST at UTC+09:00. The IANA identifiers are Asia/Colombo and Asia/Tokyo.
Does daylight saving time affect the Colombo–Japan difference?
Neither zone observes daylight saving time, so the +3h 30m offset between Colombo and Japan 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 Japan?
Not normally. The +3h 30m gap only pushes the date over for late-evening times.
What is the time difference between Colombo and Japan?
Japan 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 Japan in?
Japan 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 JST timezone?
Major cities in the JST timezone include Tokyo, Osaka, Yokohama, Nagoya, Sapporo, Kyoto, Kobe, Fukuoka.
What is the UTC offset for JST?
Japan Standard Time (JST) is at UTC+09:00.
What should I know about the JST timezone?
Japan does not observe daylight saving time. Tokyo is the most populous metropolitan area in the world.
When is it midnight in Colombo, what time is it in Japan?
When it is 12:00 AM (midnight) in Colombo (IST), it is +3h 30m later in Japan (JST).
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