Nasıl bir datetime türü ile geçti 5 Menüet dönemlerde miktarını hesaplayabilirsiniz?

bu mümkün mü?

//Update AP (+1 points every 5 mins)

//          PLAN OF ACTION (for ap update)!
// 1. check how long it has been since last update 
// 2. calculate how many 5 min periods has passed 
// 3. update $ap accordinly 
if ($last_ap_update != "0000-00-00 00:00:00"){ //Make sure last_ap_update has a value


}
else{ //If the last update is NULL, It must be players first page load. So set datetime equal to NOW
    $query = "UPDATE `stats` SET `last_ap_update` = NOW() WHERE `member_id` = {$_SESSION['SESS_MEMBER_ID']}"; 
    $queryresult = @mysql_query($query);
}