if ($begMonth)
{
    $begDate = "$begYear\-$begMonth\-$begDay 00:00:00";
    $endDate = "$endYear\-$endMonth\-$endDay 23:59:59";
    $SQL .= " AND syslog_timestamp >= '$begDate'";
    $SQL .= " AND syslog_timestamp <= '$endDate'";
}