Help - Direct Query mode, need to use FORMAT to group all dates

[tristanweeks47]

Hello, 

I am doing a project where i need to see last 6 months of data, grouped by monthly sales, and a running total to show an upward trend. 

My dataset is too large to load as a normally would so i have had to use Direct Query as merthod of storage. Usually i would use FORMAT and group the dates that way. However as this is not an option any help would be greatly appreciatted. 

Above is the screenshot showing the running total measure i have used. But need to group all dates in September together ect. So should have 6 thick bars as opposed to the thousands i have on the screenshot above. 

Thank you