It depends on if you are doing OLTP (granular, transactional) vs OLAP (fact/date based aggregates) - dates are generally not something you'd consider in a fully normalized flow to uniqify records.

Frankly I don't think that overcounting is solved by normalizing, because it's easy to write an overcounting SQL query over perfectly normalized data.

I tried to explain the real cause of overcounting in my "Modern Guide to SQL JOINs":

https://kb.databasedesignbook.com/posts/sql-joins/#understan...