The Dates dimensions is tagged as None, and the members are in 2011-01-31, 2011-02-28 format.
I am trying to use this date member as criteria for case statement.
when ([Date].CurrentMember) >2011
I also tried using DatePart function as
when DatePart ([Date].CurrentMember, DP_YEAR)>2011 but I got an error during retrieval as "invalid date specification in function [DatePart]"