Need help with Cubeset as I am only familiar with using cubevalue. (or if there is another approach I should be taking)

Pivottable selection "Time Monthly" creates a date "April 2016". From this is a dynamic list of the next 5 months. Need to create groupings from the cell values for (60 days, 90 days, 120 days etc.) that I can use in my Cubevalue.

Example:

April 2016 - Time30 [Time Monthly].[Time Monthly].["&Time30&"]
May 2016 - Time60
June 2016 - Time90

Time 30 & Time 60 = ASTime60
Time 30 & Time 60 & Time 90 = ASTime90
Etc...

I am doing this for an Accounts Sold Report.

Example:

April 2016 Accounts Sold = 20
May 2016 Accounts Sold = 30

I cannot add these values together as they are unique... So combining the 60 day period could result in 40 Accounts Sold.