BeagleQueryPartDate * datepart = beagle_query_part_date_new ();
        BeagleTimestamp *ts = beagle_timestamp_new_from_string ("2005-12-10T05:00:00.
0000000+00:00");
        BeagleTimestamp *ets = beagle_timestamp_new_from_string ("2005-12-21T05:00:00.
0000000+00:00");
        beagle_query_part_date_set_start_date (datepart, ts);
        beagle_query_part_date_set_end_date (datepart, ets);
        beagle_query_add_part (query, datepart);