Hour, Minute difference in php - php

Question

I am looking a solution in Php.
I have a total time for a task in hh:mm:ss format. (Date is not important).
and I am entering each working time also in hh:mm:ss format. Now I have to find out the remain hours in hh:mm:ss format.
Example
16:00:00 is the assigned hours to do a task.
In different dates one employee worked 13:15:00 hours
Now I need the remaining hours as 2:45:00 in format.
If date is attached then we can do like
datetime1 = new DateTime('2014-02-11 04:04:26 AM');
$datetime2 = new DateTime('2014-02-11 05:36:56 AM');
$interval = $datetime1->diff($datetime2);
echo $interval->format('%h')." Hours ".$interval->format('%i')." Minutes";
In my case there is no date. is there any functionality in PHP to find this type of hh:mm:ss difference?

Answer 1

Convert your HH:MM:SS format to a duration in seconds, subtract them, format them back to HH:MM:SS:
function str_to_seconds($duration) {
list($h, $m, $s) = explode(':', $duration);
return $s + ($m * 60) + ($h * 3600);
}
function seconds_to_str($seconds) {
return sprintf('%02d:%02d:%02d', $seconds / 3600, $seconds / 60 % 60, $seconds % 60);
}
echo seconds_to_str(str_to_seconds('16:00:00') - str_to_seconds('13:15:00'));

Answer 2

You must convert it to timestamp, then calculate the difference and format that difference to appear like a normal date.
Something like this:
function dateDifference($date_1 , $date_2 , $differenceFormat = '%a' )
{
$datetime1 = date_create($date_1);
$datetime2 = date_create($date_2);
$interval = date_diff($datetime1, $datetime2);
return $interval->format($differenceFormat);
}

Answer 3

Super short version
$secondsDiff = abs(strtotime("2014-02-11 04:04:26 AM") - strtotime("2014-02-11 05:36:56 AM"));
echo sprintf("%02d", floor($secondsDiff / 3600)) . ":" . sprintf("%02d", floor($secondsDiff / 60 %60)) . ":" . sprintf("%02d", ($secondsDiff % 60));