Buldum lazım olan kullanır diye yazıyorum.

<?php
  
// Declare and define two dates
$date1 = strtotime("2016-06-01 22:45:00");
$date2 = strtotime("2018-09-21 10:44:01");
  
// Formulate the Difference between two dates
$diff = abs($date2 - $date1);
  
  
// To get the year divide the resultant date into
// total seconds in a year (365*60*60*24)
$years = floor($diff / (365*60*60*24));
  
  
// To get the month, subtract it with years and
// divide the resultant date into
// total seconds in a month (30*60*60*24)
$months = floor(($diff - $years * 365*60*60*24)
                               / (30*60*60*24));
  
  
// To get the day, subtract it with years and
// months and divide the resultant date into
// total seconds in a days (60*60*24)
$days = floor(($diff - $years * 365*60*60*24 -
             $months*30*60*60*24)/ (60*60*24));
  
  
// To get the hour, subtract it with years,
// months & seconds and divide the resultant
// date into total seconds in a hours (60*60)
$hours = floor(($diff - $years * 365*60*60*24
       - $months*30*60*60*24 - $days*60*60*24)
                                   / (60*60));
  
  
// To get the minutes, subtract it with years,
// months, seconds and hours and divide the
// resultant date into total seconds i.e. 60
$minutes = floor(($diff - $years * 365*60*60*24
         - $months*30*60*60*24 - $days*60*60*24
                          - $hours*60*60)/ 60);
  
  
// To get the minutes, subtract it with years,
// months, seconds, hours and minutes
$seconds = floor(($diff - $years * 365*60*60*24
         - $months*30*60*60*24 - $days*60*60*24
                - $hours*60*60 - $minutes*60));
  
// Print the result
printf("%d years, %d months, %d days, %d hours, "
     . "%d minutes, %d seconds", $years, $months,
             $days, $hours, $minutes, $seconds);
?>

Çıktısı

2 years, 3 months, 21 days, 11 hours, 59 minutes, 1 seconds