India Standard Time

What does UTC+05:30 mean?

Add 5 hours and 30 minutes to a UTC time to get IST. Subtract the same amount to go from IST to UTC. If that crosses midnight, change the date too.

Does India use daylight saving time?

India does not currently change its clocks for daylight saving. IST stays at UTC+05:30. This is reflected in the current IANA time zone database entry for Asia/Kolkata.

Your country may change its clocks. That means the difference between your local time and India can change during the year even though India’s time zone stays the same. For a future meeting, check the time zone rules for the meeting date.

Which time zone should I choose on my device?

Look for India, Kolkata or Asia/Kolkata. Some systems use the older label Calcutta. New Delhi, Mumbai, Bengaluru, Chennai and Kolkata share the same standard time.

When arranging a meeting internationally, write “India Standard Time (UTC+05:30)” and include the date. The abbreviation “IST” alone can be ambiguous outside India.

How accurate is this clock?

This site reads the time from your device and uses your browser’s time zone data to display it in India. It does not synchronize with an atomic clock or measure your clock’s error. An incorrect device time will produce an incorrect display.

The two clocks on the home page use the same instant. The page reads the device clock again every second and when you return to it, so it does not keep counting from an old page-load time.

Sources

• CSIR–National Physical Laboratory: Indian Standard Time — India’s timekeeping authority and IST offset.
• IANA Time Zone Database: Asia — current and historical rules for Asia/Kolkata.
• IANA country and time zone table — India’s Asia/Kolkata identifier.

Fact-checked 16 September 2026. This is an independent clock, not an official government time service.