function count_days($a, $b)
{
//Convert times to string format//
$datea = strtotime($a);
$dateb = strtotime($b);

//Use getdate on the strings (explodes them into array form//
//See manual for specific array column names//
$a_dt = getdate($datea);
$b_dt = getdate($dateb);

//Uses maketime to generate a numeric value for the date//
//Ive used 12, 0, 0 to specify midday every day (Using a constant time value)//
$a_new = mktime(12,0 ,0, $a_dt['mon'], $a_dt['mday'], $a_dt['year']);
$b_new = mktime(12,0 ,0, $b_dt['mon'], $b_dt['mday'], $b_dt['year']);

//Returns a rounded value devided by number of seconds in the day//
return round(($a_new - $b_new) / 86400);
}