This doesn't work: ,---- | (postmodern:query | (:select (:- :localtimestamp | (simple-date:encode-interval :hour 2 :minute 10)))) | | Database error 22007: invalid input syntax for type timestamp: "2 hours 10 minutes " | Query: (SELECT (localtimestamp - '2 hours 10 minutes ')) `---- This does work: ,---- | (postmodern:query | (:select (:- :localtimestamp (:raw "interval '2 hours 10 minutes'")))) `---- It was tested with PostgreSQL 8.0.13 and 8.2.4. SQL-IZE methods for SIMPLE-DATE objects should return escaped strings like "interval '2 hours 10 minutes'", not just "2 hours 10 minutes", and second value of SQL-IZE must be NIL: b ,---- | (:method ((arg simple-date:date)) | (multiple-value-bind (year month day) (simple-date:decode-date arg) | (format nil "date ~A" | (sql-escape-string (format nil "~4,'0d-~2,'0d-~2,'0d" year month day))))) `---- (Untested!) Perhaps, sql-escape-string can be omitted: the output has no dangerous characters anyway. ,---- | (:method ((arg simple-date:date)) | (multiple-value-bind (year month day) (simple-date:decode-date arg) | (format nil "date '~4,'0d-~2,'0d-~2,'0d'" year month day))) `---- -- Ivan Boldyrev Violets are red, Roses are blue. // I'm schizophrenic, And so am I.