Colombo to Osaka
+3h 30mColombo
ISTSOURCEOsaka
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.
About Osaka
WikipediaOsaka operates on Japan Standard Time (JST), UTC+9. As Japan's second economic center and a manufacturing hub, Osaka shares business hours with Tokyo.
Osaka Castle was originally built in 1583 and has been rebuilt several times.
Colombo vs Osaka: Offsets, DST and Best Call Times
Colombo runs on India Standard Time (IST) at UTC+05:30. Osaka runs on Japan Standard Time (JST) at UTC+09:00. That puts Colombo 3 hours 30 minutes ahead of Osaka — 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 Osaka. Midnight in Colombo is 3:30 AM in Osaka. Neither zone observes daylight saving time, so the offset between them stays constant all year.
Colombo to Osaka time conversion table
| Colombo (IST) | Osaka (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 Osaka time
- Scheduling a call from Colombo to Osaka: a 10:00 AM start in Colombo lands at 1:30 PM in Osaka, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both Colombo and Osaka 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.
- Watching a live event or market open: Colombo viewers need 12:30 PM in Osaka to catch a 9:00 AM start there, and 8:30 PM if the event is anchored to Colombo.
- 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 Osaka 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 Osaka
Both Colombo and Osaka 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 Osaka 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 Osaka (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 Osaka?
Colombo (IST, UTC+05:30) is 3 hours 30 minutes ahead of Osaka (JST, UTC+09:00). The gap is currently +3h 30m.
How do I convert Colombo time to Osaka time?
Add +3h 30m to Colombo local time. For example, 9:00 AM in Colombo is 12:30 PM in Osaka.
What time is it in Osaka right now?
Osaka 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 Osaka 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 Osaka?
Colombo is 3 hours 30 minutes ahead of Osaka. When it is 12:00 PM in Colombo it is 3:30 PM in Osaka.
Do Colombo and Osaka use different time zones?
Colombo (Sri Lanka) uses IST at UTC+05:30, while Osaka (Japan) uses JST at UTC+09:00. The IANA identifiers are Asia/Colombo and Asia/Tokyo.
Does daylight saving time affect the Colombo–Osaka difference?
Neither zone observes daylight saving time, so the +3h 30m offset between Colombo and Osaka 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 Osaka?
Not normally. The +3h 30m gap only pushes the date over for late-evening times.
What is the time difference between Colombo and Osaka?
Osaka 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 Osaka in?
Osaka operates on Japan Standard Time (JST), UTC+9. As Japan's second economic center and a manufacturing hub, Osaka shares business hours with Tokyo.
What are the business hours in Colombo?
Standard business hours in Colombo are 9:00 AM - 5:00 PM IST.
What are the business hours in Osaka?
Standard business hours in Osaka are 9:00 AM - 6:00 PM JST.
What is the best time to schedule a call between Colombo and Osaka?
The best overlap for a call is when both cities are in business hours. Colombo works 9:00 AM - 5:00 PM IST and Osaka works 9:00 AM - 6:00 PM JST (+3h 30m difference). Try scheduling during the overlapping window for maximum convenience.
What currencies are used in Colombo and Osaka?
Colombo uses LKR (Rs) while Osaka uses JPY (¥). Check current exchange rates when planning travel or business between these cities.
How do Colombo and Osaka compare in size?
Colombo has a population of approximately 752,000 (metro: 5.6 million), while Osaka has approximately 2.8 million (metro: 19 million).
What are the major landmarks in Colombo and Osaka?
Colombo is known for Galle Face Green, Gangaramaya Temple, Colombo Lotus Tower. Osaka is famous for Osaka Castle, Dotonbori, Universal Studios Japan.
Do Colombo and Osaka have stock exchanges?
Yes. Colombo has the CSE (Colombo Stock Exchange) and Osaka has the OSE (Osaka Exchange - derivatives). The +3h 30m time difference affects trading hour overlaps between these exchanges.
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 Osaka?
When it is 12:00 AM (midnight) in Colombo (IST), it is +3h 30m later in Osaka (JST).
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