from what I do is send these parameters java
Map parameter = new HashMap ();
parametro.put ("date", day + "-" + month + "-" + year);
parametro.put ("date1", day + "-" + month + "-" + year);
where the variables day, month and year I get a combobox in java, and in ireport I do is get in this way
TO_CHAR (date, 'dd-mm-yyy') Between $ P {date} and $ P {date1}
if I do it separately if you do it correctly, for example:
TO_CHAR (date, 'dd-mm-yyy') = $ P {date}
but if I do it with me sum values BETWEEN statement.
and try it with operators> =, <= and I also sum values