Cumulative Total with a specific start-end date

Hi!

The bottom graph illustrates the monthly sales of two seasons. I would like to build a cumulative line that starts in September and ends in August. 

To display the months, I am taking the Month part of the date. 

Naturally, the following DAX statement doesn't work (see top graph)

Cumulative = CALCULATE (
SUM('Sales'[Total] ),
FILTER (
ALLSELECTED( 'Sales' ),
'Sales'[Date Sold] <= MAX ( 'Sales'[Date Sold] )))

Any help, suggestion or ideas would be awesome! Thank you so much!