The delicious api allows for filtering by date in the api: http://delicious.com/help/api#posts_get

However the implmentation in zend_service_delicious is not in the correct format even though a correctly formatted date is passed through using Zend_Date.

The format that can work is (line 290 onwards):

 $parms = array();
        if ($tag) {
            $parms['tag'] = $tag;
        }
        if ($url) {
            $parms['url'] = $url;
        }
        if ($dt) {
            $parms['dt'] = $dt->get('Y-M-d')."T".$dt->get('H:m:s')."Z";
        }

        $response = $this->makeRequest(self::PATH_POSTS_GET, $parms);
        return $this->_parseXmlPostList($response);

yet the current code will output an incorrect format where months are implimented as minutes and the forward slashes do not create the literal T and Z chracters needed. If some other formatting is required before passing the date then this should be documented better in http://framework.zend.com/manual/en/zend.date.html

Current code:

$parms = array();
        if ($tag) {
            $parms['tag'] = $tag;
        }
        if ($url) {
            $parms['url'] = $url;
        }
        if ($dt) {
            $parms['dt'] = $dt->get('Y-m-d\TH:i:s\Z');
        }

        $response = $this->makeRequest(self::PATH_POSTS_GET, $parms);

        return $this->_parseXmlPostList($response);