Nova Metrics - change start date of range

I might be missing something but it seems to me that the ranges used with Nova metrics always have to start from today.

So for example, I can easily show the total sales from the last month or the last 2 months or the last 3 months, etc but I can't show the total sales in just the previous month or the month before that.

I would like to have a metric where the range is by month. So the drop down would be a list of the months. Something like...

This month, Last month, May, April, March, February, January, December, November, ...

Does anyone know if this is possible without custom building the metric?