How To Sort Matrix Columns When Using Calculated Column?

[TLW_STL]

I created a matrix, using a calculated column.  The data displayed is correct, but I'd rather that my columns sort in the opposite direction. 

In the screen shot below, I show the calculated column.  Is there a way that I can change the calculation to sort data from left to right?  If not, should I create another column using INDEX?  Or maybe RANKX?  

I also have a link to a similar file saved to OneDrive, in case someone wants to review.

Thanks for any suggestions!

https://onedrive.live.com/?cid=7E43163E8AB99B59&id=7E43163E8AB99B59%21955&parId=7E43163E8AB99B59%211...

[vicky_]

you will need to create a custom sort column for your months, and thn go to Column tools > Sort by Column > [your calculated column].

I used the following DAX in my calculated column:

month sort = RANKX('Table', 'Table'[Month], , DESC)