*
* @todo strtotime() only accepts English strings. This means the expiry input
* can only be specified in English.
- * @see https://secure.php.net/manual/en/function.strtotime.php
+ * @see https://www.php.net/manual/en/function.strtotime.php
*
* @param string $expiry Whatever was typed into the form
* @return string|bool Timestamp or 'infinity' or false on error.