What's a Leap Year? Leap Year Calculator

Leap Year Definition:

"A leap year is a year containing one extra day in order to keep the calendar year synchronized with the astronomical or seasonal year."

So, a leap year in the Gregorian calender has 366 days where as a normal year has 365 days. The extra day is added in the month of February making it 29 days.

The Next Leap Year:

The next leap year is in current year 2012 and hence, February 2012 has 29 days.

Leap Year Algorithm:

Here is the Pseudocode from Wikipedia to determine whether a year is a leap year or not in either the Gregorian calendar since 1582 or in the proleptic Gregorian calendar before 1582:

if year modulo 4 is 0
then
if year modulo 100 is 0
then
if year modulo 400 is 0
then
is_leap_year
else
not_leap_year
else is_leap_year
else not_leap_year

Leap Year Calculator:

Enter the year you wish to check