Question

what is leap year ? how it is formed

Answer 1

Leap year consist of 366 days, occurring once every four years. February 29 is added as an extra day at the end of February month. The earth takes 365 and 1/ 4^th days to move round the sun. It would be very inconvenient to add fraction of a day. Hence 1/4^th day i.e. 6 hours is saved up to 4 years to make 24 hours or an extra day.