datetime - PHP date compare older than 15 days

Question

i am struggling for a long time to set a specific date but i am not getting correct out put. i want to get date from user and compare that date with the date 15 days older then today. if it is older than 15 days then convert to today else print what it is.

$todaydate= $_GET['date'];// getting date as 201013 ddmmyy submitted by user
$todaydate=preg_replace("/[^0-9,.]/", "", $todaydate); 
$today =date("dmy"); //today ddmmyy
$older= date("dmy",strtotime("-15 day")); // before 15 days 051013
if ($todaydate <= $older){
$todaydate= $today;}

problem is, it is taking date as number and giving wrong result.

Answer 1

Comparing date strings is a bit hacky and prone to failure. Try comparing actual date objects

$userDate = DateTime::createFromFormat('dmy', $_GET['date']);
if ($userDate === false) {
    throw new InvalidArgumentException('Invalid date string');
}
$cmp = new DateTime('15 days ago');
if ($userDate <= $cmp) {
    $userDate = new DateTime();
}

Also, strtotime has some severe limitations (see http://php.net/manual/function.strtotime.php#refsect1-function.strtotime-notesand) and is not useful in non-US locales. The DateTime class is much more flexible and up-to-date.