How can I add DATE_FORMAT on the server side script?

Hi there!
I'm am using the Server side (PHP) script to help me load the data faster when the page loads. Much like the example here: http://datatables.net/release-datatables/examples/data_sources/server_side.html

I have it working for the most part, however, I cannot figure out how to convert a timestamp from one of my columns in the database to just a date (such as MM/DD/YYYY) or the time (HH:MM am/pm). If I don't apply a date formatter, then I get the exact same timestamp in two columns; which prevents me from having the option to sort the table by time or date. I tried replacing one of my columns with a mysql DATE_FORMAT function to apply the date or time, but then I got an error that says

 "Unknown column 'DATE_FORMAT(timeStamp,'%b %e, %Y')' in 'field list' 

If you have any ideas on how I can apply the DATE_FORMAT on one of my columns from the DataBase, then please do share. Otherwise, I cannot move forward and I will have to rely on javascript to load most of the data.

Below is my "server_side_process.php" script:

<?php
    include 'functions.php';
    $customerID = 65;
    
    /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
     * Easy set variables
     */
    
    /* Array of database columns which should be read and sent back to DataTables. Use a space where
     * you want to insert a non-database field (for example a counter or static image)
     */
    $aColumns = array( "DATE_FORMAT(timeStamp,'%b %e, %Y')", "DATE_FORMAT(timeStamp,'%h:%i %p')", 'identifier', 'identifier', 'viewed_Type' );
    
    /* Indexed column (used for fast and accurate table cardinality) */
    $sIndexColumn = "--id--";
    
    /* DB table to use */
    $sTable = "--table--";
    
    /* Database connection information */
    $gaSql['user']       = "--USER--";
    $gaSql['password']   = "--password--";
    $gaSql['db']         = "--db--";
    $gaSql['server']     = "--server--";
    
    /* REMOVE THIS LINE (it just includes my SQL connection user/pass) */
    //include( $_SERVER['DOCUMENT_ROOT']."/datatables/mysql.php" );
    
    
    /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
     * If you just want to use the basic configuration for DataTables with PHP server-side, there is
     * no need to edit below this line
     */
    
    /* 
     * MySQL connection
     */
    $gaSql['link'] =  mysql_pconnect( $gaSql['server'], $gaSql['user'], $gaSql['password']  ) or
        die( 'Could not open connection to server' );
    
    mysql_select_db( $gaSql['db'], $gaSql['link'] ) or 
        die( 'Could not select database '. $gaSql['db'] );
    
    
    /* 
     * Paging
     */
    $sLimit = "";
    if ( isset( $_GET['iDisplayStart'] ) && $_GET['iDisplayLength'] != '-1' )
    {
        $sLimit = "LIMIT ".mysql_real_escape_string( $_GET['iDisplayStart'] ).", ".
            mysql_real_escape_string( $_GET['iDisplayLength'] );
    }
    
    
    /*
     * Ordering
     */
    $sOrder = "";
    if ( isset( $_GET['iSortCol_0'] ) )
    {
        $sOrder = "ORDER BY  ";
        for ( $i=0 ; $i<intval( $_GET['iSortingCols'] ) ; $i++ )
        {
            if ( $_GET[ 'bSortable_'.intval($_GET['iSortCol_'.$i]) ] == "true" )
            {
                    $sOrder .= "`".$aColumns[ intval( $_GET['iSortCol_'.$i] ) ]."` ".
                        mysql_real_escape_string( $_GET['sSortDir_'.$i] ) .", ";
            }
        }
        
        $sOrder = substr_replace( $sOrder, "", -2 );
        if ( $sOrder == "ORDER BY" )
        {
            $sOrder = "";
        }
    }
    
    
    /* 
     * Filtering
     * NOTE this does not match the built-in DataTables filtering which does it
     * word by word on any field. It's possible to do here, but concerned about efficiency
     * on very large tables, and MySQL's regex functionality is very limited
     */
    $sWhere = "";
    if ( isset($_GET['sSearch']) && $_GET['sSearch'] != "" )
    {
        $sWhere = "WHERE (";
        for ( $i=0 ; $i<count($aColumns) ; $i++ )
        {
            $sWhere .= "`".$aColumns[$i]."` LIKE '%".mysql_real_escape_string( $_GET['sSearch'] )."%' OR ";
        }
        $sWhere = substr_replace( $sWhere, "", -3 );
        $sWhere .= "AND customerIdentifier = '" . $customerID . "' AND (viewed_Type = 'i' or viewed_Type = 'ir' or viewed_Type = 'y' or viewed_Type = 'iry'))";
    } else {
        $sWhere .= "WHERE customerIdentifier = '" . $customerID . "' AND (viewed_Type = 'i' or viewed_Type = 'ir' or viewed_Type = 'y' or viewed_Type = 'iry') ";
    }
    
    /* Individual column filtering */
    for ( $i=0 ; $i<count($aColumns) ; $i++ )
    {
        if ( isset($_GET['bSearchable_'.$i]) && $_GET['bSearchable_'.$i] == "true" && $_GET['sSearch_'.$i] != '' )
        {
            if ( $sWhere == "" )
            {
                $sWhere = "WHERE ";
            }
            else
            {
                $sWhere .= " AND ";
            }
            $sWhere .= "`".$aColumns[$i]."` LIKE '%".mysql_real_escape_string($_GET['sSearch_'.$i])."%' ";
        }
    }
    
    
    /*
     * SQL queries
     * Get data to display
     */
    $sQuery = "
        SELECT SQL_CALC_FOUND_ROWS `".str_replace(" , ", " ", implode("`, `", $aColumns))."`
        FROM   $sTable
        $sWhere
        $sOrder
        $sLimit
        ";
    $rResult = mysql_query( $sQuery, $gaSql['link'] ) or die(mysql_error());
    
    /* Data set length after filtering */
    $sQuery = "
        SELECT FOUND_ROWS()
    ";
    $rResultFilterTotal = mysql_query( $sQuery, $gaSql['link'] ) or die(mysql_error());
    $aResultFilterTotal = mysql_fetch_array($rResultFilterTotal);
    $iFilteredTotal = $aResultFilterTotal[0];
    
    /* Total data set length */
    $sQuery = "
        SELECT COUNT(`".$sIndexColumn."`)
        FROM   $sTable
    ";
    $rResultTotal = mysql_query( $sQuery, $gaSql['link'] ) or die(mysql_error());
    $aResultTotal = mysql_fetch_array($rResultTotal);
    $iTotal = $aResultTotal[0];
    
    
    /*
     * Output
     */
    $output = array(
        "sEcho" => intval($_GET['sEcho']),
        "iTotalRecords" => $iTotal,
        "iTotalDisplayRecords" => $iFilteredTotal,
        "aaData" => array()
    );
    
    while ( $aRow = mysql_fetch_array( $rResult ) )
    {
        $row = array();
        for ( $i=0 ; $i<count($aColumns) ; $i++ )
        {
            if ( $aColumns[$i] == "version" ) {
                
                /* Special output formatting for 'version' column */
                $row[] = ($aRow[ $aColumns[$i] ]=="0") ? '-' : $aRow[ $aColumns[$i] ];
                
            } else if ( $aColumns[$i] == "identifier" ) {
                
                // GrabsMoreInformation to show
                $row[] = ($i==2) ? moreInformation($aRow[$aColumns[$i]]) : $aRow[$aColumns[$i]];
                
            } else if ( $aColumns[$i] == "viewed_Type" ) {
                /* Show Icons instead of the letter... */
                if ($aRow[$aColumns[$i]] == 'y' || $aRow[$aColumns[$i]] == 'iry') {
                    $row[] = '<img src="../images/non-view.png" title="" style="height:30px;" />';
                } else if ($aRow[$aColumns[$i]] == 'i' or $aRow[$aColumns[$i]] == 'ir') {
                    $row[] = '<img src="../images/viewed.png" title="" style="height:30px;" />';
                } else {
                    $row[] = '<img src="../img/icons/alert.png" />';
                } 
                //$row[] = $aRow[$aColumns[$i]];
                
            } else if ( $aColumns[$i] != ' ' ) {
                /* General output */
                $row[] = $aRow[ $aColumns[$i] ];
            }
        }
        $output['aaData'][] = $row;
    }
    
    echo json_encode( $output );
?>

Thank you for you time.