- var_dump: documentation ( source)
<?php
$yearMonth = '2017-06';
$firstDayOfThisMonth = new \DateTime($yearMonth . '-01');
var_dump($firstDayOfThisMonth->format('W'));
$lastDayOfThisMonth = clone $firstDayOfThisMonth;
$lastDayOfThisMonth = $lastDayOfThisMonth->modify('last day of this month');
var_dump($lastDayOfThisMonth->format('W'));
$startDate = new \DateTime($firstDayOfThisMonth->format('Y') . 'W' . $firstDayOfThisMonth->format('W'));
$endDate = new \DateTime($lastDayOfThisMonth->format('Y') . 'W' . $lastDayOfThisMonth->format('W'));
$endDate->modify('+6 days 23:59:59');
var_dump($startDate);
var_dump($endDate);
$startDate = new \DateTime($yearMonth . '-01');
$endDate = clone $startDate;
$startDate->modify('monday this week');
$endDate->modify('sunday this week');
var_dump($startDate);
var_dump($endDate);