Interactive Report Bind variable not working ?

Question

Hello,
i am new to APEX and trying to find how to use APEX Interactive Reports them with bind variables. So, i have created one with the following query:
SELECT i1.if_bic_code, b.bicname, count(*) cnt
FROM IF_DATA i1, bic b
WHERE i1.if_bic_code = b.biccode(+)
AND i1.insert_date BETWEEN :P40_X1 AND :P40_X2
GROUP BY i1.if_bic_code, b.bicname
The Report is supposed to show a count of submissions per bic_code (=bicname) from the table IF_DATA for the specified time period.
These 2 bind variables are actually 2 Items in the same region, using a Date Picker for them. They have no initial values. So, the report initially displays no records. After either using the Date Picker or manually entering values in these 2 Items, and pressing Go button still displays no rows. Am i missing something here? It seems that either the query is not submitted again to database, or the bind variables are not taken the values entered to them.
TIA

Answer 1

I tried with the date mask you proposed with no success though. It seems that it does not take into consideration the values of those items (variables) and i am wondering whether i have missed any step in this. The items are also of Date type with those settings for them under Source Group:
Source Used
Always, replacing any existing value in session state Only when current value in session state is null
Source Type
Static Assignment (value equals source attribute)
My aim is to filter the rows in the where statement through these variables(items), so this way letting the user specify the range and also display the report with the grouped values. The date field (insert_date) is not part of the Select part of the sql statement.
Also if i eliminate the date part of the where clause of the sql statement, the report displays correctly, but of course with the full date range, which is not what i want.