Here are some resources for tracking the in between months.
I think the main part is that the two sources are cross-joined (rather than blended)
on a calculated field (or columnkey) or 1.
Attached in the Forum thread is an implementation of the above for your example.
Another method is described here:
264726date.twbx 1.2 MB
Thank you very much! This is exactly what I needed, I really appreciate the help.