date calculate formula in php code example

Example 1: calculate person age by birthdate php

public function getAge($date)
    {
        
        $dob = new DateTime($date);
        
        $now = new DateTime();
         
        $difference = $now->diff($dob);
         
        $age = $difference->y;
         
        return  $age;
    }

Example 2: how to calculate days between two dates in php

<?php
function dateDifference($start_date, $end_date)
{
    // calulating the difference in timestamps 
    $diff = strtotime($start_date) - strtotime($end_date);
     
    // 1 day = 24 hours 
    // 24 * 60 * 60 = 86400 seconds
    return ceil(abs($diff / 86400));
}
 
// start date 
$start_date = "2016-01-02";
 
// end date 
$end_date = "2016-01-21";
 
// call dateDifference() function to find the number of days between two dates
$dateDiff = dateDifference($start_date, $end_date);
 
echo "Difference between two dates: " . $dateDiff . " Days ";
?>