Generate random data for highcharts

<?php

$begin = new Datetime();
$begin->modify('first day of this month');
$begin->setTime(0,0,0);

$end = new Datetime();
$end->modify('last day of this month');
$end->setTime(23,59,59);

$offset = $begin->getOffset();

$interval = new DateInterval('P1D');
$daterange = new DatePeriod($begin, $interval ,$end);

$data = [];

foreach($daterange as $date) {
    $number = mt_rand(0, 5);
    $data[] = "[" . ($date->getTimestamp() + $offset) * 1000 . ", " . $number . "]";
}

echo implode(",<br>", $data);