Almost everything a data warehouse is asked to do involves dates: days, weeks, months, years, periods of interest, special days. These date details “are attached to virtually every fact table to allow [easy] navigation…” (Source: Kimball Group)
A date dimension consolidates these details in one place in your data warehouse, delivering these benefits:
- Every part of your warehouse understands dates and their attributes in the same way
- Common understanding reduces the burden on bespoke ETL code to calculate dates to satisfy reporting requirements
- Ability to traverse to any other grouping of dates, eg from months to quarters, or quarters to years
Read about our standards for date dimensions [here] and a how-to [here]
If you’re after a master file of dates and an agile process for building a date dimension, check out our Master Date Files repository here.