Quickbase Analytics: Improve your monthly insights by implementing a Months table

This is the article I think I needed, but there are missing details in the steps that seem to be assumed.  I.e. It's missing details on the Related Month field and how to set that up. What type of field should it be?  It says how to use a pipeline to update a record when a Date field changes, but how do you initially get all of the records to fill in?  Why won't my Date field show up on the dropdown for reference fields on my parent table when I try to make the connection?  Please add more details.  Thanks.