- function_exists: documentation ( source)
- date_default_timezone_set: documentation ( source)
- date: documentation ( source)
- strtotime: documentation ( source)
<?php
if (function_exists('date_default_timezone_set')) {
date_default_timezone_set("Europe/London");
}
echo date('m/Y', strtotime("-5 month", strtotime("first day of this month")));
echo date('m/Y', strtotime("-5 month", strtotime("first day this month")));