Max value from Member Property - max

Question

I need to get the max value of a member property to use in another MDX expression.
As an example from Adventure Works I'm using the following
WITH
MEMBER DoFP AS
[Customer].[Customer].Properties("Date of First Purchase")
MEMBER MaxDoFP AS
Tail
(
NonEmpty
(
[Date].[Date].[Date]
,[Measures].[DoFP]
)
,1
).Item(0).MemberValue
SELECT
[Date].[Calendar Year].[Calendar Year] ON 0
,{
[Customer].[Customer].&[20075]
,[Customer].[Customer].&[15568]
,[Customer].[Customer].&[20285]
} ON 1
FROM [Adventure works]
WHERE
[Measures].[DoFP];
I'd like it to return June 15, 2008 for all rows/cols which is the date of first purchase for Aaron Alexander (who has the max DoFP of the customers selected) so that I can do some more calcs. Instead its giving me 31st Dec 2010 because (I assume) that's the last date in my [Date].[Date].[Date].

Answer 1

Not pretty:
WITH
SET X AS
{
[Customer].[Customer].&[20075]
,[Customer].[Customer].&[15568]
,[Customer].[Customer].&[20285]
}
MEMBER DoFP AS
[Customer].[Customer].Properties("Date of First Purchase")
MEMBER MaxDoFP1 AS
Max(DoFP)
MEMBER MaxDoFP2 AS
Max
(
X
,Cdate([Customer].[Customer].Properties("Date of First Purchase"))
)
SELECT
[Date].[Calendar Year].[Calendar Year] ON 0
,
X * {[Measures].[MaxDoFP1],[Measures].[MaxDoFP2]} ON 1
FROM [Adventure works];

Answer 2

Another option (assuming you have the ability to extend the cube structure) would be to create a measure group based on the customer dimension using a MAX aggregation function. I imagine performance would be a bit better for larger sets.
WITH
SET X AS
{
[Customer].[Customer].&[20075]
,[Customer].[Customer].&[15568]
,[Customer].[Customer].&[20285]
}
MEMBER MaxDoFP AS
Max (X,[Measures].[Customer DoFP MAX])
SELECT
[Date].[Calendar Year].[Calendar Year] ON 0
,X * {[Measures].[MaxDoFP]} ON 1
FROM [Adventure works];