- mktime: documentation ( source)
- date: documentation ( source)
- strtotime: documentation ( source)
<?php
$var1 = date('M', 1403806493);
$var2 = date('d', 1403806493);
$var3 = date('Y', 1403806493);
echo strtotime(date("M-d-Y H:i:s", mktime(23, 59, 59, $var2, $var1, $var3)));