The expressions i am using in just sum(sales), The issue is with the script. And the 03/02/2016 is just a current date that is used. So that we show a comparison of today Vs 4th of every month. We just needed to change the 4th so that user may compare today with either 1st,2nd, or 3rd as well.
Well marcus actually we have a date in the final app but when you will see the script in the attached file we are picking on the qvd of 4th of every month so even if we use date we dont have qvd of that date in the final app. i hope this helps