- time: documentation ( source)
- date: documentation ( source)
- strtotime: documentation ( source)
<?php
echo $phpdate = strtotime('-2 day');
echo PHP_EOL;
$mysqldate = date('Y-m-d H:i:s', $phpdate);
$phpdate = time();
echo $last_midnight = $phpdate - ($phpdate % (24*60*60));
?>