Conto delle ore all'interno di un mese

[k.b]

Prova cosi':

function days_in_month($month, $year) {
    $start = date('Y-m-d', mktime(0, 0, 0, $month, 1, $year));
    $end   = date('Y-m-t', strtotime($start));

    $current = $start;
    $days = array();

    while ($current <= $end) {
        $weekday = date('D', strtotime($current));
        if (!isset($days[$weekday])) {
            $days[$weekday] = 0;
        }

        $days[$weekday]++;

        $current = date('Y-m-d', strtotime("{$current} +1 day"));
    }

    return $days;
}

$days = days_in_month(4, 2015);
print_r($days); 

output:

Array
(
    [Wed] => 5
    [Thu] => 5
    [Fri] => 4
    [Sat] => 4
    [Sun] => 4
    [Mon] => 4
    [Tue] => 4
)