Total The Hours - HELP!

[ipwnzphp]

I have a app that i am working on and it has got me a lil fired up this am!! lol. here is what i am trying to do.

 

My Issue

I am trying to get the total number of hours worked form the db by adding the start_time and the end_time together.

 

My Code Snippet

<?
$results = mysql_query("SELECT * FROM `simp_time_logger` WHERE p_id = '$id'") or die (mysql_error());
while ($rows = mysql_fetch_array($results)) {
$explode_time = explode(" ", $rows['start_time']);
$explode_time2 = explode(" ", $rows['end_time']);
$start =  $explode_time[0];
$end =  $explode_time2[0];
$time = $start + $end;
}
echo $time;
?>

 

My Error

Says the number of hours worked is 16, How can this be when the start time is 8:29:55 and the end time is 8:29:57

 

Now the time is stored in the db like this 8:29:55 AM i am using explode to break off the AM/PM form it. I just need it to read the rows of the table and then get the correct total of hours worked to display.

 

Any help will be greatly appreciated. Thanks!

[al]

 

Convert to seconds do the math and convert back to HH:MM:SS.

 

 

<?php
function time_to_sec($time) {
    $hours = substr($time, 0, -6);
    $minutes = substr($time, -5, 2);
    $seconds = substr($time, -2);

    return $hours * 3600 + $minutes * 60 + $seconds;
}

function sec_to_time($seconds) {
    $hours = floor($seconds / 3600);
    $minutes = floor($seconds % 3600 / 60);
    $seconds = $seconds % 60;

    return sprintf("%d:%02d:%02d", $hours, $minutes, $seconds);
}
?>

[ignace]

How can this be when the start time is 8:29:55 and the end time is 8:29:57

 

It is because of how PHP handles strings (http://php.net/manual/en/language.types.string.php#language.types.string.conversion)

 

When you did

 

$time = $start + $end;

 

It converted both $start and $end to an integer (because of the + operand) resulting $start in 8 and $end in 8 which make your 16 total.

 

while ($row = mysql_fetch_array($results, MYSQL_ASSOC)) {
    $start = strtotime($row['start_time']);
    $end = strtotime($row['end_time']);
    $diff = $end - $start;
    $hours = floor($diff / 3600);
    $minutes = floor($diff % 3600 / 60);
    $seconds = $diff % 60;
    echo date('d M Y', $start), ' + ', date('H:m:s', mktime($hours, $minutes, $seconds)), ' = ', date('d M Y', $end);
}

 

Chances are this can be written a lot shorter.