Working Days

<?php
date_default_timezone_set('Europe/Sofia');
$startDate = DateTime::createFromFormat('d-m-Y', $_GET['dateOne']);
$endDate = DateTime::createFromFormat('d-m-Y', $_GET['dateTwo']);
$holidays = preg_split('/\s+/', $_GET['holidays'], -1, PREG_SPLIT_NO_EMPTY);
$workingDays = array();
$date = $startDate;
while ($date <= $endDate) {
    $dateStr = $date->format('d-m-Y');
    $dayOfWeek = $date->format('D');
    if (!in_array($dateStr, $holidays) && $dayOfWeek != 'Sun' && $dayOfWeek != 'Sat') {
        array_push($workingDays, $dateStr);
    }

    date_add($date, date_interval_create_from_date_string('1 day'));
}

$result = '<h2>No workdays</h2>';
if (count($workingDays)) {
    $result = '<ol>';
    foreach ($workingDays as $day) {
        $result .= "<li>{$day}</li>";
    }
    $result .= '</ol>';
}

echo $result;