Need To Display Month Wise And Quarter Wise Charts In Cognos

Hi All,

I need to create a chart in Cognos which should  represents Month wise and quarter wise Marketing segments from the given dates. Actually, I've produced chart based on day wise through below expression for  date parameter in Cognos report studio.

_add_days(2015-09-02,_days_between([wt.inf.library.WTLibrary=Enquiry].[MarketSegment vs DateOf Creation for August Month].[master>thePersistInfo.createStamp],2015-09-02)).

And got chart like below..

But, I  need to display  month wise Marketing segment with corresponding months and quarter wise Marketing segments with three months as a group with string names like quarter1...  When I'm trying to give _add_month expression getting validatin errors.

Kindly request to help me to achieve this as this is my high priority task.

Thanks in advance

Regards,

Krishna Chaithanya