GMT to IST Converter
Convert Greenwich Mean Time (GMT/BST) to India Standard Time (IST) instantly. See live clocks, convert any time, and view a full hour-by-hour comparison chart — free, no signup required.
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GMT to IST — Hour-by-Hour Comparison
| GMT (Greenwich) | IST (India) |
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Frequently Asked Questions
IST (India Standard Time) is 5 hours and 30 minutes ahead of GMT (Greenwich Mean Time). This means when it is noon (12:00 PM) in London, it is 5:30 PM in Mumbai, Delhi, Bangalore, Chennai, and Kolkata.
To convert GMT to IST, add 5 hours and 30 minutes. For example: 3:00 PM GMT = 8:30 PM IST. To convert IST to GMT, subtract 5 hours and 30 minutes: 3:00 PM IST = 9:30 AM GMT.
India does not observe daylight saving time. However, the UK switches to BST (British Summer Time, GMT+1) from late March to late October. During BST, the difference between London and India becomes 4 hours 30 minutes instead of 5 hours 30 minutes.
India uses a single time zone (IST, UTC+5:30) for the entire country. The 30-minute offset was chosen as a compromise to represent the geographical center of India. This helps align the clock more closely with solar noon across India's wide east-west span, rather than using a full-hour offset like UTC+5 or UTC+6.