Online PHP editor | output for efGi3

<?php Class MyCalendar { public $free = array(); public $booked = array(); public function __construct($week = 'now') { $start = new DateTime($week); $start->modify('Monday this week midnight'); $end = clone $start; $end->modify('Friday this week midnight'); $interval = new DateInterval('P1D'); foreach (new DatePeriod($start, $interval, $end) as $freeTime) { $this->free[] = $freeTime; } } public function bookAppointment(DateTime $date, $note) { $this->booked[] = array('date' => $date->modify('midnight'), 'note' => $note); } public function checkAvailability() { return array_udiff($this->free, $this->booked, array($this, 'customCompare')); } public function customCompare($free, $booked) { if (is_array($free)) $a = $free['date']; else $a = $free; if (is_array($booked)) $b = $booked['date']; else $b = $booked; if ($a == $b) { return 0; } elseif ($a > $b) { return 1; } else { return -1; } } } // Create a calendar for weekly appointments $myCalendar = new MyCalendar; // Book some appointments for this week $myCalendar->bookAppointment(new DateTime('Monday this week'), "Cleaning GoogleGuy's apartment."); $myCalendar->bookAppointment(new DateTime('Wednesday this week'), "Going on a snowboarding trip."); $myCalendar->bookAppointment(new DateTime('Friday this week'), "Fixing buggy code."); // Check availability of days by comparing $booked dates against $free dates echo "I'm available on the following days this week...\n\n"; foreach ($myCalendar->checkAvailability() as $free) { echo $free->format('l'), "\n"; } echo "\n\n"; echo "I'm busy on the following days this week...\n\n"; foreach ($myCalendar->booked as $booked) { echo $booked['date']->format('l'), ": ", $booked['note'], "\n"; } ?>