Date difference using PHP | Learning Curve- Perfect Tutorial for the beginers

<?php

// start date comes here
$start_date='2010-11-10';

//end date come here-or you can use today's timestamp

$end_date='2014-06-16';

//converting the start and end date to timestamp

$start_date_timestamp=strtotime($start_date);
$end_date_timestamp=strtotime($end_date);

$time_difference=abs($start_date_timestamp - $end_date_timestamp);
echo $time_difference;

//ouput:113526000

// Converting this difference as in days

//difference in days
$days = $time_difference/(60*60*24);
echo 'Days '.$days;

//ouput:1313.9583333333

//difference in months
$months = $time_difference/(60*60*24*30);
echo 'Months '.$months;

//ouput:43.798611111111

//difference in Years
$years = $time_difference/(60*60*24*365);
echo 'Years '.$years ;
//ouput: 3.5998858447489

?>

<?php

// start date comes here

$start_date='2010-11-10';

//end date come here-or you can use today's timestamp

$end_date='2014-06-16';

//converting the start and end date to timestamp

$start_date_timestamp=strtotime($start_date);

$end_date_timestamp=strtotime($end_date);

$time_difference=abs($start_date_timestamp - $end_date_timestamp);

echo $time_difference;

//ouput:113526000

// Converting this difference as in days

//difference in days

$days = $time_difference/(60*60*24);

echo 'Days '.$days;

//ouput:1313.9583333333

//difference in months

$months = $time_difference/(60*60*24*30);

echo 'Months '.$months;

//ouput:43.798611111111

//difference in Years

$years = $time_difference/(60*60*24*365);

echo 'Years '.$years ;

//ouput: 3.5998858447489