Modify result from AdminController

[set4812]

I easy downloading data from my table in databases. This is simple code what i have now

    public function __construct()
   {
    //$this->context = Context::getContext();
    $this->table = 'auctions_rutcom_bids';
    //$this->identifier = 'id_auctions_rutcom';
       $this->className = 'archiwumclass';
    $this->_defaultOrderBy = 'id_auctions_rutcom_bids';
    $this->lang = TRUE;
    $this->addRowAction('delete');

    $this->bulk_actions = array('delete' => array('text' => $this->l('Delete selected'),
			    'confirm' => $this->l('Delete selected items?')), );

   // Shop::addTableAssociation($this->table, array('type' => 'shop'));

       $this->fields_list = array(
           'id_auctions_rutcom_bids' => array('title' => $this->l('ID'), 'align' => 'center', 'width' => 25),
           'id_auctions_rutcom' => array('title' => $this->l('Id auction'), 'align' => 'center', 'width' => 25),
           'id_customer' => array('title' => $this->l('Id costumer bind'), 'align' => 'center', 'width' => 25),
           'bid_value' => array('title' => $this->l('Bid Value'), 'align' => 'center', 'width' => 25),
       );

    parent::__construct();
   }

This is possible to change result what i taking from db? I need filter records and only take where date>NOW()

Thx for help

set4812