Calculate number of weekends per month, quarter, and year

numweekendsbyyear.php

#!/usr/bin/env php
<?php

if(!isset($argv[1]) or !is_numeric($argv[1]) or strlen($argv[1]) != 4){
$cmd = $argv[0];
echo <<<out
See the number of weekend in each month, quarter, and yearly.

Usage: $cmd yyyy

ex: $cmd 2010
ex: $cmd 1999
ex: $cmd 2200

out;
exit(1);
}

$el = PHP_EOL;
$year = $argv[1];
echo "Year:\t".$year.$el.$el;
echo "Item\tNum WE".$el;
$yearDays = 0;
$quaterDays = 0;
$quarter = 1;
for($month=1;$month<=12;$month++){
    echo date('M',mktime(0,0,0,$month,1,$year)).":\t";
    $daysInMonth = date('t',mktime(0,0,0,$month,1,$year));
    $weekendDays = 0;
    for($day=1;$day<=$daysInMonth;$day++){
        $weekDayNum = date('N',mktime(0,0,0,$month,$day,$year));
        if(in_array($weekDayNum,array(5,6,7))){
            $weekendDays++;
            $quaterDays++;
            $yearDays++;
        }
    }
    echo round($weekendDays/3,2).$el;
    if(in_array($month,array(3,6,9,12))){
        echo 'Q'.$quarter.":\t";
        echo round($quaterDays/3,2).$el;
        $quaterDays = 0;
        $quarter++;
    }
}

echo 'Year'.":\t";
echo round($yearDays/3,2).$el;

?>