Periods of calculation

[#1]

Hello,

For productions statistics, I would like a table showing stat for a specifc week and the same table with the same stats but for a period going from a specific fixed date to the week selected previously.

For the first table, it's not hard to change form week to week, but for the second one, I'm not able to secify a period of calculation into the parameters of the table.

Let say for example that the stats for Machine A have to be calculated from September 1, how could I write this condition and where?

Thanks a lot!
Vincent

[#2]

The variable looks like this: =concat(distinct(week(JC_OPE_DATE)))

and in a textbox it comes out correctly: one value.