IST to JST Converter
Convert time between India Standard Time (IST) and Japan Standard Time (JST)
India Standard Time (IST)
Japan Standard Time (JST)
Time Difference
Japan Standard Time (JST) is 0 hours ahead of India Standard Time (IST)
Select Date
Select Time
Quick Reference
| IST | JST |
|---|---|
| 07:30 | 11:00 |
| 09:30 | 13:00 |
| 11:30 | 15:00 |
| 13:30 | 17:00 |
| 15:30 | 19:00 |
| 17:30 | 21:00 |
| 19:30 | 23:00 |
| 21:30 | 01:00 |
| 23:30 | 03:00 |
| 01:30 | 05:00 |
| 03:30 | 07:00 |
| 05:30 | 09:00 |
Top 10 Most Common Time Zones
| Abbreviation | Full Name | UTC Offset | Typical Use |
|---|---|---|---|
| UTC | Coordinated Universal Time | UTC ±0 | Global reference standard (servers, logs, APIs) |
| EST / EDT | Eastern (US) Time | UTC −5 / −4 | New York, Toronto — North American business hub |
| CST / CDT | Central (US) Time | UTC −6 / −5 | Chicago, Dallas — US central business region |
| PST / PDT | Pacific (US) Time | UTC −8 / −7 | San Francisco, Los Angeles — tech industry standard |
| GMT / BST | Greenwich Mean / British Summer Time | UTC 0 / +1 | UK, used globally as a reference with UTC |
| CET / CEST | Central European (Summer) Time | UTC +1 / +2 | Paris, Berlin, Amsterdam — EU business core |
| IST | India Standard Time | UTC +5:30 | India — major IT & outsourcing region |
| CST | China Standard Time | UTC +8 | Beijing, Shanghai — East Asia business hub |
| JST | Japan Standard Time | UTC +9 | Tokyo — finance & tech hub |
| AEST / AEDT | Australian Eastern (Daylight) Time | UTC +10 / +11 | Sydney, Melbourne — APAC regional business |
Why Time Zone Abbreviations Are Ambiguous
Unlike standardized identifiers (like America/New_York or Europe/London from the IANA tz database), abbreviations such as "CST" or "IST" are not globally unique. They can refer to different time zones depending on context — country, region, or even time of year (due to daylight saving time).
Common Ambiguous Time Zone Abbreviations
| Abbrev. | Common Meaning(s) | UTC Offset | Region(s) |
|---|---|---|---|
| CST | Central Standard Time / China Standard Time / Cuba Standard Time | UTC−6 / UTC+8 / UTC−5 | North America, China, Cuba |
| IST | Indian Standard Time / Irish Standard Time / Israel Standard Time | UTC+5:30 / UTC+1 / UTC+2 | India, Ireland, Israel |
| AST | Atlantic Standard Time / Arabia Standard Time | UTC−4 / UTC+3 | Caribbean, Canada, Middle East |
| PST | Pacific Standard Time / Philippine Standard Time | UTC−8 / UTC+8 | North America, Philippines |
| EST | Eastern Standard Time (North America / Australia) | UTC−5 / UTC+10 | North America, Australia |
✅ Best Practice
To avoid ambiguity, always:
- Use IANA tz identifiers — e.g.,
America/New_Yorkinstead of "EST" - Specify UTC offset explicitly — e.g.,
UTC−5when abbreviations must be used - Include the full timezone name — e.g., "Eastern Standard Time (EST)" with UTC offset
About IST to JST Time Conversion
Converting time from India Standard Time (IST) to Japan Standard Time (JST) is essential for India-Japan coordination. IST is UTC+5:30 and JST is UTC+9, making JST 3.5 hours ahead of IST. Neither India nor Japan observe daylight saving time, so this offset is constant year-round.
This moderate gap supports a broad overlap in business hours — afternoons in India align with the latter half of the Japanese workday. Whether you're coordinating with Tokyo, Osaka, or Yokohama teams, our IANA-based converter delivers reliable results in every season.
Common Use Cases for IST to JST Conversion
Business & Work
- Scheduling calls between Indian teams and Tokyo or Osaka offices
- Coordinating engineering, manufacturing, or fintech projects between India and Japan
- Planning daily standups that fit both Indian and Japanese working hours
Personal & Travel
- Keeping in touch with family or friends living in Japan
- Planning travel from India to Tokyo, Kyoto, or Osaka
- Scheduling online study, anime watch parties, or virtual events across both regions
Time Zone Information
India Standard Time (IST)
- UTC Offset: UTC+5:30
- IANA Timezone: Asia/Kolkata
- Daylight Saving: No daylight saving time (consistent year-round)
- Major Cities: New Delhi, Mumbai, Bangalore, Hyderabad, Chennai, Kolkata
- Coverage: Entire India (single timezone covering the nation)
Japan Standard Time (JST)
- UTC Offset: UTC+9 (no DST observed)
- IANA Timezone: Asia/Tokyo
- Daylight Saving: Japan does not observe daylight saving time
- Major Cities: Tokyo, Osaka, Kyoto, Yokohama, Nagoya, Sapporo, Fukuoka
- Coverage: All of Japan
Quick Reference: IST to JST
Remember: JST is always 3.5 hours ahead of IST. Neither region observes daylight saving time, so this offset is constant.
Frequently Asked Questions
What is the time difference between IST and JST?
India Standard Time (IST) is UTC+5:30, while Japan Standard Time (JST) is UTC+9. JST is 3.5 hours ahead of IST, so when it is 9:00 AM in Delhi, it is 12:30 PM in Tokyo.
Does the IST to JST time difference change throughout the year?
No. Neither India nor Japan observes daylight saving time. IST stays at UTC+5:30 and JST stays at UTC+9 every day of the year, so the 3.5-hour gap is constant.
How do half-hour offsets affect this conversion?
IST sits on a half-hour offset (UTC+5:30) while JST does not, so conversions land on :30 minutes (e.g. 9:00 AM IST → 12:30 PM JST).
What are the best times to schedule IST to JST business calls?
Overlap is good. 9 AM–2 PM IST is 12:30–5:30 PM JST — strong for live calls covering most of the Japanese afternoon and the start of the Indian workday. Earlier IST times (7–9 AM) catch late-morning Japan if you need a longer Japanese block.
Which regions and cities use JST?
JST (UTC+9) is used by all of Japan. Major cities include Tokyo, Osaka, Kyoto, Yokohama, Nagoya, Sapporo, and Fukuoka.
Which regions use IST?
IST (UTC+5:30) covers all of India under a single timezone. Major cities include New Delhi, Mumbai, Bangalore, Hyderabad, Chennai, and Kolkata. India does not observe daylight saving time.
Pro Tips
- • JST is always 3.5 hours ahead of IST — add 3:30 to Indian time.
- • Neither region observes DST, so this conversion is constant year-round.
- • Morning India (9–11 AM IST) is mid-day Japan (12:30–2:30 PM JST) — a strong window for live collaboration.
- • Late-afternoon India (3–5 PM IST) is late evening in Japan (6:30–8:30 PM JST), so push major calls earlier in the Indian day.
- • Japan observes Golden Week (late April to early May) and Obon (mid-August), when business activity slows — plan around these.
- • JST shares its UTC+9 offset with KST, so a single Tokyo-Mumbai call can also include Korean partners.