Actually all I did was that I created a pivot chart with two dimensions and one expression.
The two dimensions I use is week and dayname.
Expression is weekdate. =WeekDate
Week(ActualStartTime) as Week,
Day(ActualStartTime) as WeekDate,
WeekDay(ActualStartTime) as DayName
Then I left click the DayName and drag it to the top of the chart.(Not sure what that is called)
One problem with this method is that if you do not have any sales on a given day, that day will not appear in the chart.
I assume I could correct this by adding an inline fucntion where I just create a set from 1 to 31 and called that weekdate
In your case I guess you would need the expression =sum(sales)