Calculate number of days between two dates except holidays

<?php
function getDays($dateStart, $dateEnd)
{
	 // Get time stamp
     $dateStartTS = strtotime($dateStart);
     $dateEndTS = strtotime($dateEnd);
     $dateDiff = $dateEndTS - $dateStartTS;
     return floor($dateDiff/(60*60*24));
}
 
echo $totalDays = getDays('2015-08-01', '2015-08-30');
// => will return 29
?>

<?php
function getDays($dateStart, $dateEnd) {
    $dateStartTS = new DateTime($dateStart);
    $dateEndTS = new DateTime($dateEnd);
    $interval = $dateStartTS->diff($dateEndTS);
    return $interval->format('%R%a days');
}
echo $totalDays = getDays('2015-08-01', '2015-08-30');
// => will return 29
?>

<?php
//The function returns the no. of business days between two dates and it skips the holidays
function getWorkingDays($startDate,$endDate,$holidays){
    // do strtotime calculations just once
    $endDate = strtotime($endDate);
    $startDate = strtotime($startDate);
 
 
    //The total number of days between the two dates. We compute the no. of seconds and divide it to 60*60*24
    //We add one to inlude both dates in the interval.
    $days = ($endDate - $startDate) / 86400 + 1;
 
    $no_full_weeks = floor($days / 7);
    $no_remaining_days = fmod($days, 7);
 
    //It will return 1 if it's Monday,.. ,7 for Sunday
    $the_first_day_of_week = date("N", $startDate);
    $the_last_day_of_week = date("N", $endDate);
 
    //---->The two can be equal in leap years when february has 29 days, the equal sign is added here
    //In the first case the whole interval is within a week, in the second case the interval falls in two weeks.
    if ($the_first_day_of_week <= $the_last_day_of_week) {
        if ($the_first_day_of_week <= 6 && 6 <= $the_last_day_of_week) $no_remaining_days--;
        if ($the_first_day_of_week <= 7 && 7 <= $the_last_day_of_week) $no_remaining_days--;
    }
    else {
        // (edit by Tokes to fix an edge case where the start day was a Sunday
        // and the end day was NOT a Saturday)
 
        // the day of the week for start is later than the day of the week for end
        if ($the_first_day_of_week == 7) {
            // if the start date is a Sunday, then we definitely subtract 1 day
            $no_remaining_days--;
 
            if ($the_last_day_of_week == 6) {
                // if the end date is a Saturday, then we subtract another day
                $no_remaining_days--;
            }
        }
        else {
            // the start date was a Saturday (or earlier), and the end date was (Mon..Fri)
            // so we skip an entire weekend and subtract 2 days
            $no_remaining_days -= 2;
        }
    }
 
    //The no. of business days is: (number of weeks between the two dates) * (5 working days) + the remainder
//---->february in none leap years gave a remainder of 0 but still calculated weekends between first and last day, this is one way to fix it
   $workingDays = $no_full_weeks * 5;
    if ($no_remaining_days > 0 )
    {
      $workingDays += $no_remaining_days;
    }
 
    //We subtract the holidays
    foreach($holidays as $holiday){
        $time_stamp=strtotime($holiday);
        //If the holiday doesn't fall in weekend
        if ($startDate <= $time_stamp && $time_stamp <= $endDate && date("N",$time_stamp) != 6 && date("N",$time_stamp) != 7)
            $workingDays--;
    }
 
    return $workingDays;
}
 
//Example:
 
$holidays=array("2008-12-25","2008-12-26","2009-01-01");
 
echo getWorkingDays("2008-12-22","2009-01-02",$holidays)
// => will return 7
?>