Converting A Date Field

[Sheldon]

If the value of [My]![Date]![Field] = 'Jun 30, 2009 12:00:00 AM' and I would like to display 2009-06-30, I tried using a filter in my query as follows:
to_char([My].[Date].[Field],'yyyy-mm-dd')

RQP-DEF-0217 Wrong expression type: to_char([State Level Student Identification].[Student Identification].[School Year],'yyyy').RQP-DEF-0149 The query specification is incorrect.RQP-DEF-0457 Referenced Query 'Query1' is not defined or its query items contain unresolved references.

I am pulling from an Oracle datanbase.  If I remove the filter, I don't get an error and the report runs.  I have no idea why this doesn't work.  I also find that there are so few, if any, examples in the IBM documentation.  A 714 page manual and all it says is:
***
to_char
Returns the character string "date_exp" with the specified "string_exp" formatting. You can use
this function only with built-in data types.
Syntax
to_char ( date_exp, string_exp )
***
Thanks for any/all suggestions. 

[rockytopmark]

You say you are trying to change the "Display" of your date item, not the actual value...  Why not just adjust the Data Format property??

Use the Pattern setting (the very last setting for Date) And set to:  yyyy-MM-dd

New-------------Raw----------------------------
2009-12-09 ---- Dec 9, 2009 6:39:29 AM
2009-11-16 ---- Nov 16, 2009 12:19:55 PM
2009-11-16 ---- Nov 16, 2009 12:24:52 PM

[Sreeni P]

yeah it wil works in all the ways....but be sure in ur model the dateacolumn usage property will be 'Attribute'