Filter Due During Previous X Months vs Quarters

Please make the filter "due during previous" that I use in views related to projects coherent. It behaves differently for x quarters and x months.
If I select "due during previous" x quarters, I don't see what has a due date in January. It seems right.
If I select "due during previous" x months, I do see what is due in January (current month) as well. It seems wrong.

For future reference, the feature request ID is CR-654858.