India uses a permanent UTC+5:30 offset. That makes India time stable, but comparisons with countries that use daylight saving time can change during the year. For example, India is 5 hours 30 minutes ahead of the UK during GMT but 4 hours 30 minutes ahead during British Summer Time. India is 10 hours 30 minutes ahead of New York during US standard time but 9 hours 30 minutes ahead during US daylight saving time.
When scheduling important meetings, use city-based time zones in calendar apps: Asia/Kolkata for India, Europe/London for the UK, America/New_York for Eastern US, Asia/Dubai for UAE and Australia/Sydney for Sydney. City-based time zones allow the calendar to handle seasonal clock changes automatically.