- time: documentation ( source)
- date: documentation ( source)
- strtotime: documentation ( source)
<?php
$startTs = time();
// for testing
$startTs = strtotime('05/03/2015');
$baseDay = strtotime('+1', $startTs);
echo $ts = date('d.m.Y', strtotime('last sunday', $baseDay));
echo PHP_EOL;
echo $ts = date('d.m.Y', strtotime('this saturday', $baseDay));