<!-- Collection of code snippets by Arne Vajhøj -->
<!-- posted to eksperten.dk, usenet and other places (2002-now) -->
<?php
class Interval {
    public $from;
    public $to;
    public function __construct($from, $to) {
        $this->from = $from;
        $this->to = $to;
    }
}

class OpenDay {
    public $day;
    public $openAt;
    public function __construct($day, $openAt) {
        $this->day = $day;  
        $this->openAt = $openAt;    
    }
}

function aggregate($open) {
    $res = array();
    $first = $open[0]->day;
    for($i = 1; $i < 7; $i++) {
        if(($open[$i]->openAt->to != $open[$i-1]->openAt->to) ||
           ($open[$i]->openAt->from != $open[$i-1]->openAt->from)) {
            $last = $open[$i-1]->day;
            $res[] = new OpenDay($first . '-' .$last, $open[$i-1]->openAt);
            $first = $open[$i]->day;
        }
    }
    $last = $open[6]->day;
    $res[] = new OpenDay($first . '-' .$last, $open[6]->openAt);
    return $res;
}

$open = array();
$open[] = new OpenDay('Monday', new Interval('05:30', '22:00'));
$open[] = new OpenDay('Tuesday', new Interval('05:30', '22:00'));
$open[] = new OpenDay('Wednesday', new Interval('05:30', '22:00'));
$open[] = new OpenDay('Thursday', new Interval('05:30', '22:00'));
$open[] = new OpenDay('Friday', new Interval('05:30', '22:00'));
$open[] = new OpenDay('Saturday', new Interval('06:30', '22:00'));
$open[] = new OpenDay('Sunday', new Interval('06:30', '22:00'));

print_r($open);

$aggropen = aggregate($open);

print_r($aggropen);
?>