Here. Some wise man gave this to me a long time ago.. and now I pass it on to you.
$timestamp = time();
$date_time_array = getdate($timestamp);
$hours = $date_time_array["hours"];
$minutes = $date_time_array["minutes"];
$seconds = $date_time_array["seconds"];
$month = $date_time_array["mon"];
$day = $date_time_array["mday"];
$year = $date_time_array["year"];
// use mktime to recreate the unix timestamp
$timestamp = mktime($hours, $minutes,$seconds ,$month, $day,$year);
You would find your date by saying that you want to add 6 months to mktime and get a result.
would look somehting like this.
$timestamp = time();
$date_time_array = getdate($timestamp);
$hours = $date_time_array["hours"];
$minutes = $date_time_array["minutes"];
$seconds = $date_time_array["seconds"];
$month = $date_time_array["mon"];
$day = $date_time_array["mday"];
$year = $date_time_array["year"];
// use mktime to recreate the unix timestamp
$timestamp = mktime($hours, $minutes,$seconds ,$month + 6, $day,$year);