CakePHP "Expires" behavior. Works with 1.2. I don't think any changes are required to get it working with 2.0. Ensure you've added `expiry_date` (DATE) column to your model table.

expires.php

<?php

class ExpiresBehavior extends ModelBehavior {

  protected $_defaults = array(
    'field' => 'expiry_date'
  );

/**
 * Setup this behavior with the specified configuration settings.
 *
 * @param object $model Model using this behavior
 * @param array $config Configuration settings for $model
 * @access public
 */
  function setup(&$model, $config = array()) {

    // merge existing settings or defaults with the model config
    $this->settings[$model->alias] = array_merge(
      isset($this->settings[$model->alias]) ? $this->settings[$model->alias] : $this->_defaults,
      $config
    );

    // throw exception if the model's db field doesn't exists in the db table
    if (!array_key_exists($this->settings[$model->alias]['field'], $model->_schema)) {
      throw new Exception(
        sprintf(
          "%s field does not exist in the %s table",
          $this->settings[$model->alias]['field'],
          $model->useTable
        ),
      1);
    }
  }

/**
 * Before find callback
 *
 * @param object $model Model using this behavior
 * @param array $queryData Data used to execute this query, i.e. conditions, order, etc.
 * @return boolean True if the operation should continue, false if it should abort
 * @access public
 */
  function beforeFind(&$model, $query) {

    // if a condition is already set, then do nothing
    if (array_key_exists($this->settings[$model->alias]['field'], $query)) {
      return $query;
    }

    // merge existing query with the expiry condition
    return Set::merge($query, array(
      'conditions' => array(
        // return records that have their expiry date in the future
        $model->alias . '.' . $this->settings[$model->alias]['field'].' >=' => date('Y-m-d')
      )
    ));
  }
}

?>

gist.php

<?php

class Gist extends AppModel {

  var $name = 'Gist';
  
  // include Expires behavior
  var $actsAs = array(
    'Expires'
  );
}

?>