Changing the default parameter on a deployed report in SSRS

Question

I have a report that has a default date range (Start Date -> End Date) that is set to a week using a formula. I have been asked to create a subscription to this report but it needs to be fortnightly not weekly.

The subscription only seems to acecpt the current default (which is a week), or a specific date range. I am sure my users don't want to see the exact same report every two weeks because of the specific dates. they would like to see the previous two weeks of data.

To have the Start Date default change depending on the day it is run requires a formula for the parameter. (=DateAdd("d",-14,Now()))

The problem I have is that overriding the default will not take a formula. It only seems to take a specific value. I would prefer not to have to deploy a second report exactly the same just to allow a subscription to show different date ranges.

Answer 1

Found an answer that works for me.
I just needed to do three things

1. Add a new Hidden Parameter - called Weekly Default set to 1
2. Change the formula for the start date to =DateAdd("ww",Parameters!WeekDefault.Value, Today)
3. Move the Weekly Default Parameter to the top of the Parameter List so that it is defined first before being used.