create Dynamic variant for date field

Hello all,

I need to have the current month year displayed in my selection screen in format MM.YYYY and the field is of type SPMON (Period to analyze - month).

and while saving the variant it is showing only 'T' (entries from TVARVC table) in "selection variable" field and not showing 'D' (Dynamic selection) for the above field.

So,please help me in resolving this issue.

Thanks in advance.