SSAS RelativeCalendar CurrentYear CurrentMonth...

I have a dimension DimDate (Year, month, days, quater) and in this dimension I would like to create a relative calendar corresponding to the relative year and relative month. Eg in: - Relative Year I would like to have a Member : current year, current year-1 - Relative Month i would like to have a member : Current month, current month -1, current month-2...

how to do it in SSAS?

I add named calculations for those Relative Year, Month in my dimension DimDate

After i create calculate members like this :

[Annee en cours] => StrToMember ("[Date].[Calendar].[Calendar Year].&[" + Format(Now(),"yyyy") + "]" )

[Annee en cours -1] => StrToMember ("[Date].[Calendar].[Calendar Year].&[" + Format(Now(),"yyyy") + "]" ).Lag(1)

....

i have this error when i use the calculate members RelativeYear in my cube to have order quantity for CurrentYear, currentYear-1,...

ERROR => " A setcan notcontaincalculated membershas been detected"