Meridian
GMT to IST converter
Convert GMT to IST for London ↔ India. A 4.5–5.5 hour gap with a solid mid-morning overlap — see the shared work hours on one drag timeline.
How GMT to IST actually works
India Standard Time is UTC+5:30 with no daylight saving. London is GMT (UTC+0) in winter and BST (UTC+1) from late March to late October. So the gap is 5 hours 30 minutes for about five months and 4 hours 30 minutes for the rest — India is always ahead of London.
Unlike New York–India, this pair has a genuinely usable overlap: London's morning is India's afternoon. The planner above
keeps Europe/London and Asia/Kolkata on one UTC minute so you can pick a slot that is mid-day for both.
Typical overlapping work hours
- Winter (GMT): about 09:00–12:00 London / 14:30–17:30 India.
- Summer (BST): about 09:00–13:00 London / 13:30–17:30 India — the window widens.
- Best slot: 10:00–11:00 London / 15:30–16:30 India, comfortable on both sides.
Convert a specific time
- The planner already has London and Mumbai loaded.
- Drag either bar to your proposed hour — both rows stay on the same UTC moment.
- Read the green overlap band, then copy the invite with both local times.
GMT to IST — frequently asked questions
What is the time difference between GMT and IST?
5 hours 30 minutes on GMT; 4 hours 30 minutes when London is on BST (late March to late October). India never changes clocks.
Is IST ahead of or behind GMT?
Ahead. 12:00 London is 17:30 India on GMT, or 16:30 India on BST.
What are the overlapping work hours for London and India?
Roughly 09:00–12:00 London / 14:30–17:30 India in winter, widening on BST. One of the friendlier long-haul pairs.
Does this account for British Summer Time?
Yes — it uses Europe/London, so BST applies automatically and the gap drops to 4.5 hours in summer.