How to subtract two date using PHP not difference

Question

I am a newbie programmer, I would like to know how I can subtract two dates

My sample is

$datetoday = date("Y/m/d");
$dateprev = "2015/11/03";

All I want is, if $datetoday is greater than $dateprev , that the output is a positive value.

If $dateprev is greater than $datetoday , the output should be a negative value.

Answer 1

You can use strtotime function on those dates to turn them into integers (unix/epoch timestamp) and compare them that way.

And the time() function will get the current date/time directly as the unix timestamp.

Answer 2

You can use these code for date difference :-

<?php
     $val1 = '2014-03-18 10:34:09.939';
     $val2 = '2014-03-18 10:34:09.940';

     $datetime1 = new DateTime($val1);
     $datetime2 = new DateTime($val2);

    if($datetime1 > $datetime2)
        echo "1 is bigger";
    else
        echo "2 is bigger";
?>

Answer 3

You could use diff from the DateTime Interface. Here is a code example:

$datetoday = new DateTime();
$dateprev = new DateTime('2015/11/03');
$interval = $dateprev->diff($datetoday);
echo $interval->format('%R%a');