Mark your calendars

A great way to organize different time series data is to have a date dimension table. Power Pivot has a feature that allows us to easily create and customize a calendar table for our data model.

Having a date table also makes it easier to connect different fact tables. For example, loans_data and sales_goals_2021 are fact tables with dates. loan_data has closing_date, but sales_goals_2021 has month. If we were to join these tables together directly, we would only get the Goal on the loan_id that has a closing_date that matches the first of the month; however, we want the sales goal to match to the month of the closing_date. Therefore, a date table can act as a link to join these two tables together seamlessly.

Continue working in your current workbook. If you've lost progress, open 2_2_hierarchies.xlsx from the Workbooks folder in the course materials.