Google Data Studio offers some powerful reporting features, but one piece we’re still waiting on is more control over comparisons — right now you can compare your data against the “previous period” or “previous year”, the latter of which gives you a same-date comparison year-over-year. However, a common requirement is being able to report on the same weekday year-over-year.
Over on the Napkyn blog, I wrote up my detailed (and consequently long) overview of how to accomplish day-of-week comparisons year-over-year with Data Studio and Google Analytics. The solution provides Google Analytics 360 customers with a way to accomplish this by using the GA integration with Google BigQuery.
Have a look, and let me know if you have any feedback in the comments!