Number of working hours in a month.

Dear all, How do I dynamically calculate how many working hours in a particular month? Has anyone do it before? Here is the simple formula. Add - Number of days in a month Deduct - Sundays Number of Mon-Fri in a month * 8 hours Number of Sat in a month * 4 hours My Figure = total working hours of a month. I do not need to include any holidays. This data is for my monthly timesheets. Currently I am hard coding it while I find a solution... I have almost managed to get the info that I wanted. Below is the script and it works almost for all the months except for some... I would say about 92%, 1 in 12 incorrect... Can anyone help to debug and find a formula to get this working? <? $month=11; $year=2002; $num_of_days = date("t", mktime(0,0,0,$month,1,$year)); echo "Month=$month Year=$year <BR>"; echo "Number of days = $num_of_days <BR>"; // count how many weeks in the month have a specified day, such as Monday. // we know there will be 4 or 5, so no need to check for $weeks<4 or $weeks>5 $firstdayname = date("D", mktime(0, 0, 0, $month, 1, $year)); $firstday = date("w", mktime(0, 0, 0, $month, 1, $year)); $lastday = date("t", mktime(0, 0, 0, $month, 1, $year)); echo "First day of the month = $firstdayname <BR> "; for ($day_of_week = 0; $day_of_week <= 6; $day_of_week++) {

    if ($firstday > $day_of_week) {
        // means we need to jump to the second week to find the first $day_of_week
        $d = (7 - ($firstday - $day_of_week)) + 1;
        echo "d=$d ";
    } elseif ($firstday < $day_of_week) {
        // correct week, now move forward to specified day
        $d = ($day_of_week - $firstday + 1);
        echo "d=$d ";
    } else {    // $firstday = $day_of_week
        // correct day in first week
        $d = ($firstday - 1);
        echo "d=$d ";
    }

    $d += 28;    // jump to the 5th week and see if the day exists
    echo "(Final D=$d > $lastday) ";
    if ($d > $lastday) {
        $weeks = 4;
    } else {
        $weeks = 5;
    }
    echo "$day_of_week occurences = $weeks <BR> ";

} ?>