Incrementing days if day is a workday

Answer 1

date('N', $theDate) gives you the day of the week (6 for Saturday and 7 for Sunday). From there, you can easily implement a function that does only counts workdays. On the other hand, this does not detect holidays.

Answer 2

Quick iteration:

$days = 0;
for($i = time(); $i < (strtotime('29.07.2010') + 86400); $i=$i+86400)
{
    $weekday = date('w', $i);
    if($weekday > 0 &&  $weekday < 6)
    {
       $days++; 
    }
}

echo $days;