CODE EXAMPLE FOR PHP

Diferencia entre dias PHP - Con date_diff()

<?php
  
  // Creates DateTime objects
  $datetime1 = date_create('17-09-2018');
  $datetime2 = date_create('25-09-2018');
  
  // Calculates the difference between DateTime objects
  $interval = date_diff($datetime1, $datetime2);
  
  // Display the result
  echo $interval->format('Difference between two dates: %R%a days');
?>