Method to determine whether a year is a leap year

How to determine whether a year is a leap year

  1. If the year is evenly divisible by 4, go to step 2. Otherwise, go to step 5.
  2. If the year is evenly divisible by 100, go to step 3. Otherwise, go to step 4.
  3. If the year is evenly divisible by 400, go to step 4. Otherwise, go to step 5.
  4. The year is a leap year (it has 366 days).
  5. The year is not a leap year (it has 365 days).
<?php
function is_leap_year1( $year )
{
	if ((($year % 4 == 0) AND ($year % 100 != 0)) OR ($year % 400 == 0))
		return true; // is leap year
	else
		return false; // not a leap year
}
 
function is_leap_year2($year)
{
	if( $year % 400 == 0)
	{
		return true; // is leap year
	}
 
	else if ($year % 100 == 0)
	{
		return false; // not a leap year
	}
 
	else if($year % 4 == 0)
	{
		return true; // is leap year
	}
 
	else
	{
		return false; // not leap year
	}
}
 
$year = @$_GET['year'] ? $_GET['year'] : 2008;
print '<pre>';
var_dump( $year ) ."\n";
var_dump( is_leap_year1($year)) ."\n";
var_dump( is_leap_year2($year)) ."\n";
?>

About this entry

Title: Method to determine whether a year is a leap year

Published:
14.08.08
Category:
alert