Valid UK Date Function
function is_valid_date($value, $format = 'dd/mm/yyyy'){
if(strlen($value) >= 6 && strlen($format) == 10){
// find separator. Remove all other characters from $format
$separator_only = str_replace(array('m','d','y'),'', $format);
$separator = $separator_only[0]; // separator is first character
if($separator && strlen($separator_only) == 2){
// make regex
$regexp = str_replace('mm', '(0?[1-9]|1[0-2])', $format);
$regexp = str_replace('dd', '(0?[1-9]|[1-2][0-9]|3[0-1])', $regexp);
$regexp = str_replace('yyyy', '(19|20)?[0-9][0-9]', $regexp);
$regexp = str_replace($separator, "\\" . $separator, $regexp);
if($regexp != $value && preg_match('/'.$regexp.'\z/', $value)){
// check date
$arr=explode($separator,$value);
$day=$arr[0];
$month=$arr[1];
$year=$arr[2];
if(@checkdate($month, $day, $year))
return true;
}
}
}
return false;
}