No, you don't just want a set
You have two real options here
Option 1 is creating measures such as Gross Revenue YTD, Net Revenue YTD etc (depending on the measure you have)
An example from one of my cubes is just to create lots of measures such as
CREATE MEMBER CURRENTCUBE.[Measures].[Net Revenue YTD]
AS
SUM(PERIODSTODATE([Date].[Date Hierarchy].[Year],[Date].[Date Hierarchy].CurrentMember)
,[Measures].[Net Revenue])
,FORMAT_STRING = "#,#.00"
,VISIBLE = 1;
The other slightly more complicated option is to create a dimension not linked to your data with you time calcs in it (query that just returns YTD, MTD etc)
You can then use a SCOPE statement to define the value of each member of the Time Calcs dimension such as
SCOPE ([Time Calcs].[Calc Name].&[YTD]);
THIS =
SUM(PERIODSTODATE([Date].[Date Hierarchy].[Year],[Date].[Date Hierarchy].CurrentMember)
,[Time Calcs].[Calc Name].[All] );
END SCOPE;
Option 2 probably needs more explaination (try http://www.bidn.com/blogs/Qazafi/ssas/1020/an-other-example-of-calculation-dimension) and I personally prefer option 1 anyway
Shout if I've lost you
Mack