PHP has DateTime and DateInterval objects which can be used like this:
$date1 = new DateTime("2024-03-24");
$date2 = new DateTime("2025-05-08");
$interval = $date1->diff($date2);
echo "difference " . $interval->y . " years, " . $interval->m." months, ".$interval->d." days ";
// shows the total amount of days (not divided into years, months and days like above)
echo "difference " . $interval->days . " days ";
Also, DateTime objects can be compared using comparison operators.
$date1 = new DateTime("now");
$date2 = new DateTime("tomorrow");
var_dump($date1 == $date2); // bool(false)
var_dump($date1 < $date2); // bool(true)
var_dump($date1 > $date2); // bool(false)