ssas - Execution of the managed stored procedure Format failed with the following error: Microsoft::AnalysisServices::AdomdServer::AdomdException

Question

Below is my mdx query written in microsoft analysis services:

            WITH
            MEMBER [Measures].[DateMax] AS
                STRTOMEMBER("[INT TIME].[INT TIME].&["+Format([Measures].[2013-08-29T00:00:00], 'yyyy-MM-ddTHH:mm:ss')+"]")

            MEMBER [Measures].[DateBefore3Months] AS
                Format(DateAdd('m', -2, [Measures].[DateMax]), 'yyy-MM-01T00:00:00')

            SELECT
            non empty { [Measures].[DURATION],
                [Measures].[SELL VALUE],
                [Measures].[BUY VALUE],      
                [Measures].[PERCENTAGE]}  on columns,
            non empty (
                {STRTOMEMBER("[INT TIME].[INT TIME].&["+[Measures].[DateBefore3Months]+"]"):STRTOMEMBER("[INT TIME].[INT TIME].&["+[Measures].[DateMax]+"]")},
                [CUSTOMER PROFILES].[CUSTOMER].[CUSTOMER]
                ) on rows
            FROM [Cube1]

The error i am getting is :

Execution of the managed stored procedure Format failed with the following error: Microsoft::AnalysisServices::AdomdServer::AdomdException. Query (3, 72) The '[2013-08-29T00:00:00]' member was not found in the cube when the string, [Measures].[2013-08-29T00:00:00], was parsed.

Please suggest where is the problem in this query and how can I resolve it.