- date: documentation ( source)
- strtotime: documentation ( source)
<?php
$startDate = "2015-08-01";
$endDate = "2015-08-31";
$startDate = strtotime($startDate);
$endDate = strtotime($endDate);
for($i = strtotime('Friday', $startDate); $i <= $endDate; $i = strtotime('+1 week', $i))
echo date('l Y-m-d', $i).PHP_EOL;