MUN Issues ,need to cast the timestamp when using lastmonth

Hi ,

I have a member unique name which is for Feb 2017 as below

[SalesCube].[Time Period].[Time Period].[Months]->:[PC].[@MEMBER].[20170201-20170228]

I am generating this mun using below macro

#'[SalesCube].[Time Period].[Time Period].[Months]->:[PC]....