Check whether a year is a leap year
The following function checks whether a given year is a leap year.
<?php
function is_leap_year($year) {
return $year%4==0 && ($year%100!=0 || $year%400==0);
}
?>
Explanation
Per definition, a year is leap year if it can be divided by 4, but not by 100
except it can be divided by 400.
In short: Every 4 years, except centuries, but every 4th century.
So the year 2000 was a leap year for example, because it can be divided by
4, (100) and 400.