JST ↔ IST Time Converter

India Standard Time (IST) is 3h 30m behind of Japan Standard Time (JST). This comes from JST being at UTC+9 and IST at UTC+5:30. Three quick examples: 9:00 AM JST = 5:30 AM IST; 12:00 PM JST = 8:30 AM IST; 5:00 PM JST = 1:30 PM IST.

To convert JST to IST, subtract 3 hours 30 minutes to the JST time. For example: 12:00 PM JST → 8:30 AM IST. When the result goes past midnight, increment the date by one day (shown as "+1 Day" in the converter). Because IST uses a :30 offset, results will always land on a :30-minute mark — carry the 30 minutes forward normally.

India Standard Time (IST) is 3h 30m behind of Japan Standard Time (JST). The reverse is also true: JST is 3h 30m ahead of IST. A real-world example: if a colleague in New Delhi proposes a noon meeting, that means 3:30 PM on your JST clock in Tokyo.

Japan Standard Time (JST) is the standard civil time used across Tokyo, Osaka, Kyoto, Yokohama and surrounding regions. It sits at UTC+9 relative to UTC. It does not observe Daylight Saving Time, so the UTC offset remains constant at UTC+9 every day of the year. Major cities in this zone include: Tokyo, Osaka, Kyoto, Yokohama, Nagoya, Sapporo, Fukuoka.

India Standard Time (IST) is the civil time standard for New Delhi, Mumbai, Bangalore, Chennai and the surrounding area. Operating at UTC+5:30 from UTC, it does not observe Daylight Saving Time — the offset stays fixed at UTC+5:30 all year with no seasonal change. Cities in this zone include: New Delhi, Mumbai, Bangalore, Chennai, Kolkata, Hyderabad, Colombo.

No. Neither JST nor IST observes Daylight Saving Time. The offset between them stays constant at 3h 30m behind every single day of the year, with no seasonal adjustment on either side. This makes JST–IST one of the simpler pairs to schedule across, since you never have to recalculate for clock changes.

The best meeting window is where standard working hours (9 AM – 6 PM) overlap in both zones. Since IST is 3h 30m behind of JST, mornings in the earlier zone align with afternoons or evenings in the later zone. As a rule of thumb: 8 AM – 11 AM in the earlier zone usually works for both sides. Check the meeting hours table above for this specific pair's recommended slots, and avoid any time that falls before 7 AM or after 9 PM on either side.

Type any time into the IST field in the bidirectional converter above — it calculates the JST result instantly and works equally well in both directions. You can also add 3 hours 30 minutes from the IST time manually to get the JST equivalent. For a dedicated reverse converter, visit: IST to JST converter ↗.

For certain times of day, the conversion does cross midnight into the next or previous calendar day. When a converted time crosses 11:59 PM, the date advances by one day — shown as "+1 Day" in the converter. When it goes before 12:00 AM, the date moves back — shown as "-1 Day". The 24-hour reference table on this page also flags day changes in the Day column. Always check the date indicator when sending calendar invites or scheduling calls across these two zones.

Japan Standard Time (JST) is the official time standard for: Tokyo, Osaka, Kyoto, Yokohama, Nagoya, Sapporo, Fukuoka. The zone operates at UTC+9, with no seasonal variation. It is one of the most widely used time zones for international business in its region.

India Standard Time (IST) covers: New Delhi, Mumbai, Bangalore, Chennai, Kolkata, Hyderabad, Colombo. It runs at UTC+5:30, fixed year-round with no DST adjustment. When coordinating calls between JST and IST, use the live clocks at the top of this page to see the exact current local time in both zones simultaneously before confirming a meeting time.

India Standard Time (IST) is fixed at UTC+5:30 — a 30-minute increment rather than a whole-hour UTC offset. India uses this single nationwide zone to keep civil time reasonably close to solar noon across its wide geographic span. Because of this half-hour offset, any time you convert JST to IST, the result will always fall on a :30-minute mark (e.g., 9:00 AM JST = 5:30 AM IST).

Yes. The live clocks at the top update every second so you always see the current time in both zones. The converter handles DST changes automatically, and the 24-hour table gives you a printable reference for the full day. For recurring meetings, pick a slot from the "Best Meeting Hours" table and set your calendar event with the correct IANA timezone (Asia/Tokyo for JST, Asia/Kolkata for IST) so future occurrences self-adjust for any clock changes.