A few days ago we were trying to make some reports using iReport designer, here I put the solution for this. With this, we can design a more simple way iReport reports. in the script of the SQL query must cast the parameter input to timestamp date type or cast that comes from the database to text Ex. WHERE text(fields) == $P{incio} OR WHERE fields == $P{incio}::timestamp the jasper report to odoo module we doanload to https://github.com/germanponce/Jasper-Reports-Odoo-8 I hope to help them