IST is used for 3 different time zones. The table below shows each one with its offset and current time.
What IST can mean
The letters IST are shared by zones on different offsets. A meeting invite that says only IST can be read several ways, so add a city name or a UTC offset.
| Name | UTC offset | Time now | Used in |
|---|---|---|---|
| India Standard Time | UTC+5:30 | --:-- | Asia/Kolkata |
| Irish Standard Time | UTC+1 | --:-- | Europe/Dublin |
| Israel Standard Time | UTC+2 | --:-- | Asia/Jerusalem |
Who uses IST
| IANA time zone | Uses IST | Main cities |
|---|---|---|
| Asia/Kolkata | All year | Mumbai, Delhi, Bengaluru |
| Europe/Dublin | During daylight saving time | Dublin, Cork, Limerick |
| Asia/Jerusalem | Outside daylight saving time | Jerusalem, Tel Aviv, Haifa |
IST and IDT
IDT is the daylight saving version of IST, 2 hours 30 minutes ahead of it. Writing IST in summer means a time that is 2 hours 30 minutes off for the places that have switched.
Tools for time in IST
- Convert a time to or from IST: pick a date and time and see it in every city on your list.
- Add Mumbai to your world clock to keep it next to your own time.
- Find a meeting time that falls inside office hours in IST and the other cities you work with.
- Open a full-screen clock for your own time zone.
Frequently asked questions
Which time zone does IST mean?
It depends on who wrote it. India Standard Time (UTC+5:30): Mumbai; Irish Standard Time (UTC+1): Dublin; Israel Standard Time (UTC+2): Jerusalem. Ask for a city or a UTC offset if the context does not make it clear.
What time is 12:00 IST in UTC?
12:00 IST is 6:30 AM UTC.
Time zone rules: IANA tz database, version 2026e. Place names and coordinates: GeoNames. Sunrise and sunset are calculated from the coordinates and can differ by a minute or two from local almanacs.