dettool -pretend -simple -definebyquery -inst CFH12K -det_type bias -select_exp_type bias -dbname cfh12k -workdir path://CFH12K/detrend/bias -select_dateobs_begin 2001-02-15T21:37:00 -select_dateobs_end 2001-02-17

 dettool -pretend -simple -definebyquery -inst CFH12K -det_type dark -select_exp_type dark -dbname cfh12k -workdir path://CFH12K/detrend/dark -select_dateobs_begin 2001-03-28 -select_dateobs_end 2001-04-01