Hi, that doesn't seem to work either. it will not let me select the same dates, and it accepts an end date less than a start date. i tried swapping the LESS than and GREATER than symbols (< >) around so it looks like this :
To prevent the user to select incoherent dates, I'd do the check in a different conditional, or even in the Calculation condition of the object, so the set analysis is always like that, but the chart will not show any values because they won't make any sense.
What it does make sense also is that you may set a maximum and minimum date dynamically in your calendar objects, so once the start date is selected, and so stored in the vStartDate variable, it becomes the minimum for the end date, so the user will not be able to select one less than the other.
a) add an action (right click on the background of the sheet, properties, triggers) so when a week is selected, set variable vStartDate to take "=WeekStart(Weekfield)" as value and vEndDate "=WeekEnd(WeekField)"
b) add an action so when start date is selected, vEndDate is set to "=$(vStartDate)" so the user will never select incoherent dates.
c) in the start date calendar object, min is set to "=Min(Date)" and max is set to "=Max(Date)"
d) in the end date calendar object, min is set to "=$(vStartDate)" and max is set to "=Max(Date)"
Moreover, you can add a visible/hidden variable so the end date object will only appear if a start date is selected. The steps above should be enough, though.