JST to IST Converter
Convert time between Japan Standard Time (JST) and India Standard Time (IST)
Japan Standard Time (JST)
India Standard Time (IST)
Time Difference
India Standard Time (IST) is 0 hours ahead of Japan Standard Time (JST)
Select Date
Select Time
Quick Reference
| JST | IST |
|---|---|
| 11:00 | 07:30 |
| 13:00 | 09:30 |
| 15:00 | 11:30 |
| 17:00 | 13:30 |
| 19:00 | 15:30 |
| 21:00 | 17:30 |
| 23:00 | 19:30 |
| 01:00 | 21:30 |
| 03:00 | 23:30 |
| 05:00 | 01:30 |
| 07:00 | 03:30 |
| 09:00 | 05:30 |
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 JST to IST Time Conversion
Converting time from Japan Standard Time (JST) to India Standard Time (IST) is essential for Japan-India coordination. JST is UTC+9 and IST is UTC+5:30, making IST 3.5 hours behind JST. Neither Japan nor India observes daylight saving time, so this 3.5-hour gap is constant year-round.
This moderate, stable offset supports a wide overlap in business hours — Japanese mornings line up with the start of the Indian workday. Whether you are coordinating with Tokyo, Osaka, or Yokohama partners on tech, manufacturing, or trade projects, our IANA-based converter delivers reliable results in every season.
Common Use Cases for JST to IST Conversion
Business & Work
- Scheduling calls between Tokyo or Osaka offices and Indian teams
- Coordinating engineering, automotive, or fintech projects between Japan and India
- Planning daily standups that fit both Japanese and Indian working hours
Personal & Travel
- Keeping in touch with family or friends living in India
- Planning travel from Japan to Delhi, Mumbai, or Bangalore
- Scheduling online study, anime watch parties, or virtual events across both regions
Time Zone Information
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
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)
Quick Reference: JST to IST
Remember: IST is always 3.5 hours behind JST. Neither region observes daylight saving time, so this offset is constant.
Frequently Asked Questions
What is the time difference between JST and IST?
Japan Standard Time (JST) is UTC+9, while India Standard Time (IST) is UTC+5:30. IST is 3.5 hours behind JST, so when it is 12:00 PM in Tokyo, it is 8:30 AM in Delhi.
Does the JST to IST time difference change throughout the year?
No. Neither Japan nor India observes daylight saving time. JST stays at UTC+9 and IST stays at UTC+5:30 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. 12:00 PM JST → 8:30 AM IST).
What are the best times to schedule JST to IST business calls?
Overlap is good. 12–3 PM JST is 8:30–11:30 AM IST — strong for live calls covering Japanese lunch-and-after with the start of the Indian morning. Late afternoon JST (4–6 PM) maps to 12:30–2:30 PM IST, ideal for full-attention sessions on both sides.
Which regions and cities 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.
Which regions use JST?
JST (UTC+9) is used by all of Japan. Major cities include Tokyo, Osaka, Kyoto, Yokohama, Nagoya, Sapporo, and Fukuoka. Japan does not observe daylight saving time.
Pro Tips
- • IST is always 3.5 hours behind JST — subtract 3:30 from Japanese time.
- • Neither region observes DST, so this conversion is constant year-round.
- • Mid-day Japan (12–3 PM JST) is 8:30–11:30 AM in India — a strong window for live collaboration.
- • Early morning India (7–9 AM IST) equals late morning Japan (10:30 AM–12:30 PM JST), useful when the Japanese side wants longer working hours before the call.
- • 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.