Ad Hoc Analysis: Make any date range roll

[#1]

In 'ad hoc analysis' (formally Discover) we are restricted to 20 preset rolling date ranges.

I find this very limiting, for instance I can select a rolling date range of 'last three months' but it is impossible to create a report for the 'last 6 months' because this is not one of the presets.

Please can you consider adding a feature that allows us to make any selected date range roll relative to the current date?

(as is already available is SiteCatalyst dashboards & report builder)