Indian Standard Time is 5 hours and 30 minutes ahead of Greenwich Mean Time. In winter this is 6 hours and 30 minutes, while daylight savings time is in operation.
So to convert you have to add the time difference to the original time. In a cell type the GMT you want. So if it was 10:30am, in the appropriate cell you could type:
10:30
In another cell you would put the time difference:
5:30
You then need to add the two together. If the GMT value was in cell B2 and the time difference was in C2, then in another cell you would have the formula:
=B2+C2
You may need to reformat the cell to show the time the exact way you want. This can be done by going to the Format menu, picking Cells, and then Time and finally the format you want the time to show as.
IST is GMT+2. Therefore 1 o'clock in GMT is 3 o'clock in IST.
Add 5.30 hrs to GMT to get IST so 13.30 GMT means 19.00IST
2.30 pm ist
to what corresponds 2.30 GMT in CET
2210 IST
4 PM India Standard Time (IST) = 10:30 AM Greenwich Mean Time (GMT) 4 PM Israel Standard Time (IST) = 2 PM GMT 4 PM Irish Summer Time (IST) = 3 PM GMT
India Standard Time (IST) is 5:30 hours ahead of GMT.
If it's 17:00 GMT, the time in India will be 22:30 IST. India is 5 hours and 30 minutes ahead of Greenwich Mean Time (GMT).
2210 IST
IST is 5.5 hours ahead of GMT IST does not used Daylight Savings Time
Add 5 hours, 13.30 + 5.00 = 19.30 pm IST
Subtract one hour from a BST time to convert to GMT. To do the opposite, add one hour to a GMT time to convert to BST.