$from_time = date('Y-m-d H:i:s');
$to_time = $row['clock'];
echo $from_time - $to_time;
The $to_time is a time stamp in the MySQL database. $row['clock'] = 2013-10-27 13:28:01.
When I run this code, the echo always returns 0.
I am trying to get the amount of seconds between the dates.
You're basically trying to subtract two strings. If you echo $from_time, you can find out that the value will be something like 2013-10-27 12:49:270, and $to_time will be another string -- 2013-10-27 13:28:01.
You need to convert them into timestamps before doing the substraction:
$from_time = time();
$to_time = strtotime($row['clock']);
I recommend using the DateTime class for working with dates and times.
This is how you find the difference between two dates using DateTime class:
$from_time = new DateTime('now');
$to_time = new DateTime("2013-10-27 13:28:01");
$interval = $from_time->diff($to_time);
echo $interval->format('%h hours %i minutes %S seconds');
Output:
0 hours 31 minutes 48 seconds
first convert $to_time to timestamp using strtotime() and then subtract,only then you will get the correct result
strtotime will convert a date to UNIX a timestamp,
which is in seconds and will enable you to do your calculation.
http://php.net/manual/de/function.strtotime.php
$from_time = time();
$to_time = strtotime($row['clock']);
echo $from_time - $to_time;
strtotime(date('Y-m-d H:i:s')) -- just time() is enough.