Add 'customise dates' calendar control to the portfolio view

There is a great 'customise dates' calendar control on the Release->Roadmap and Reports->Timeline views which I would like to see implemented on the portfolio page.

This would give me more control over the timeline that is visible outside of the defined 1 Qtr, 2 Qtrs, 1 Year, 2 Years.

I'd also like the ability to set the granularity of the x-axis like you can with the same control. Quarters, and particularly months, would be very useful. For non-typical fiscal years (July to June, for example) the clarity of which months are in a given quarter would be useful in managing expectations with stakeholders.