Recurring events with cron-like syntax

gistfile1.php

<?php
date_default_timezone_set('Europe/London');

function dd()
{
	die(var_dump(func_get_args()));
}

function dp($i)
{
	die(print_r($i));
}
 
function sort_multi_array($array, $key)
{
	$keys = array();
	for ($i=1; $i < func_num_args(); $i++)
	{
		$keys[$i-1] = func_get_arg($i);
	}
	
	$func = function($a, $b) use ($keys)
	{
		for ($i=0; $i < count($keys); $i++)
		{
			if ($a[$keys[$i]] !== $b[$keys[$i]])
			{
				return ($a[$keys[$i]] < $b[$keys[$i]]) ? -1 : 1;
			}
		}
		return 0;
	};
	
	usort($array, $func);
	return $array;
}
 
function matches($day_of_month = '*', $month = '*', $day_of_week = '*', $time)
{
	
	if  (($day_of_month !== '*') && ((int) date('d', $time) !== $day_of_month))
	{
		return false;
	}
	
	if  (($month !== '*') && ((int) date('n', $time) !== $month))
	{
		return false;
	}
	
	if  (($day_of_week !== '*') && ((int) date('w', $time) !== $day_of_week))
	{
		return false;
	}
	
	return true;
}
 
function mkevent($title, $repeat_from, $repeat_until, $duration, $minute, $hour, $day_of_month, $month, $day_of_week)
{
	$e = new stdClass;
	$e->title = $title;
	$e->repeat_from = $repeat_from;
	$e->repeat_until = $repeat_until;
	$e->duration = $duration; // in minutes
	$e->minute = $minute; // * = any minute, 1 through 59
	$e->hour = $hour; // * = any hour, 1 through 59
	$e->repeat_dayofmonth = $day_of_month; // * = any day, 1 through 31
	$e->month = $month; // * = any month, 1 = Jan, 12 = Dec
	$e->repeat_dayofweek = $day_of_week; // * = any day, 0 = sunday, 6 = saturday
	return $e;
}
 
$events = array();
 
// Recurring events
$events[] = mkevent('Weekly Tuesday Meeting', '2011-12-01', '2011-12-31', 60, 30, 11, '*', '*', 2);
$events[] = mkevent('Weekly Friday Meeting', '2011-12-01', '2011-12-31', 30, '*', 16, '*', '*', 5);
$events[] = mkevent('Christmas', '2010-01-01', '2015-12-31', 1440, 0, 0, 25, 12, '*');
 
// Induvidual events
$events[] = mkevent('Lunch with John Doe', '2011-12-21', '2011-12-21', 30, '*', 12, '*', '*', '*');
$events[] = mkevent('Cinema', '2011-12-14', '2011-12-14', 180, '*', 19, '*', '*', '*');
 
$results = array();
 
foreach ($events as $k => $event)
{
	$start = strtotime($event->repeat_from);
	$end = strtotime($event->repeat_until);
	
	for ($current = $start; $current <= $end; $current += 86400)
	{
		$event->hour = ($event->hour === '*') ? 0 : $event->hour;
		$event->minute = ($event->minute === '*') ? 0 : $event->minute;
		
		$newtime = mktime($event->hour, $event->minute, 0, date('m', $current), date('d', $current), date('Y', $current));
		
		if ($i = matches($event->repeat_dayofmonth, $event->month, $event->repeat_dayofweek, $newtime))
		{
			$results[] = array(
				'event_title'	=> $event->title,
				'english_start'	=> date('l jS F Y H:i', $newtime),
				'english_end'		=> date('l jS F Y H:i', ($newtime + ($event->duration * 60))),
				'unix_start'	=> $newtime,
				'unix_end'		=> $newtime + ($event->duration * 60)
			);
		}	
	}
}
 
print_r(sort_multi_array($results, 'unix_start'));