SSRS weekly parameter not working

Question

I am trying to add a weekly parameter into my SSRS report,

I have been using

=DateAdd("d",-7, Today)

and also

=DateAdd("ww",-1, Today) 

Neither bring up the dates that I need to display there are dates from the 01/01/2014 showing up on the report.

Is there something else that needs adding into the report for this parameter to work？ I need to show all of the previous weeks data from the day the report is processed but it is showing dates that go before last Monday.

Answer 1

This will give you date for of the previous week.

=DATEDIFF(WEEK,1,[date_col])

Hope this is what you want. Your question is unclear. Add the dataset query & the report screenshot here if possible.