jQuery datepicker celper functions

<?php


// http://php.net/manual/de/function.date.php

// Zeilenumbruch
$b = "\n";
$bb = "\n\n";
$bbb = "\n\n\n";

#################################################### Umgang mit date()
#echo date("l") . $b;
#echo date('l jS \of F Y h:i:s A') . $b;
#echo "Weekday: " . date('l') . $b;
#echo "Weekday as number:" . date('w')  .$b;
#echo "Day of month as number: " . date('d') . $b;
#echo "Month: " . date('F') . $bbb;
#echo "July 27, 1981 war ein " . date("l", mktime(0, 0, 0, 7, 27, 1981)) . " und der " . date('w', mktime(0, 0, 0, 7, 27, 1981)) . "te Tag der Woche." . $b;
###################################################



/*
 * Returns the difference of months between current month and given date
 * @param $date a YYYY-MM-DD formatted date
 */
function getDiffBetweenCurMonthAndTravelMonth($date)
{	
	// current date
	$curDate = date('Y') . "-". date('m').  "-" . date('d');
	$ts1 = strtotime($curDate);
	$ts2 = strtotime($date);
	$year1 = date('Y', $ts1);
	$year2 = date('Y', $ts2);
	$month1 = date('m', $ts1);
	$month2 = date('m', $ts2);
	$diff = (($year2 - $year1) * 12) + ($month2 - $month1);
	return $diff;
}
#echo "diff month: " . getDiffBetweenCurMonthAndTravelMonth("2014-08-02") . "\n";


/**
 * Returns number of weekday
 * 1 = Montag ... 7 = Sonntag
 * @param $date a YYYY-MM-DD formatted date
 */
function getDayNumberOfWeek($date)
{
	$ts = strtotime($date);
	$year = date('Y', $ts);
	$month = date('m', $ts);
	$day = date('d', $ts);
	$numDay = date("w", mktime(0, 0, 0, $month, $day, $year));
	if ($numDay == 0) {
		return 7;
	}
    return $numDay;
}
echo "weekday number of 27.07.1981: " . getDayNumberOfWeek("1981-07-27") . "\n";


/**
 * Returns the amount of weeks into the month a date is
 * @param $date a YYYY-MM-DD formatted date
 * @param $rollover The day on which the week rolls over
 */
function getWeekOfMonth($date, $rollover)
{
	$cut = substr($date, 0, 8);
	$daylen = 86400;

	$timestamp = strtotime($date);
	$first = strtotime($cut . "00");
	$elapsed = ($timestamp - $first) / $daylen;

	$i = 1;
	$weeks = 1;

	for($i; $i<=$elapsed; $i++)
	{
		$dayfind = $cut . (strlen($i) < 2 ? '0' . $i : $i);
		$daytimestamp = strtotime($dayfind);

		$day = strtolower(date("l", $daytimestamp));

		if($day == strtolower($rollover))  $weeks ++;
	}

	return $weeks;
}

//outputs 2, for the second week of the month
#echo getWeekOfMonth("2014-07-23", "monday") . "\n"; // 4
#echo getWeekOfMonth("2014-02-02", "monday") . "\n"; // 1
#echo getWeekOfMonth("2014-02-03", "monday") . "\n"; // 2
#echo getWeekOfMonth("2011-08-01", "monday") . "\n"; // 1

?>