The year which has 366 days is called a Leap Year. That extra one day is added to the shortest month of the year, i.e. February. Thus when a year has 29th February in its calendar, it is termed as a leap year. This year occurs every four years.
OMG YES! "Dammit wrong door. SHIT, WHAT DO I DO? Okay, calm down Jim, think. Dramatic entrance. Now..wait for the right moment...3,2 and...1! Sorry boys, I'm soooo changeable! It is a weakness of mine (dude don't make them think your weak!) ...but to be fair it is my only weakness!"-slik Jim, slik! *spider drops off web and makes it look like a graceful leap*