Static dates in the report generation

I think an idea to improve that recently a client share with me was about the custom dates when they generate a report, and let me explain more about it because sounds very interesting.

In this case she wants to identify trends in the organization, and want to have the info updated to the last week, but that the starting week stays statics.

She wants to instead of keep watching the results of a year, could be: 1 year + 1 week, 1 year+ 2 weeks, etc, the only way she can do this its by creating each week a new report with the dates, but might be a gool idea to have some autoupdate split.

Regards