There is no lowercase yy for year. Did you mean to use YYYY?
Lowercase dd is a two-letter abbreviation for the Day of Week. Did you mean to use DD instead?
For more information, see tokens for formatDate link above.
Hope this helps! Let me know if there are any further questions or issues.
— @samliew
P.S.: Did you know, the concepts of about 70% of questions asked on this forum are already covered in the Make Academy. Investing some effort into it will save you lots of time and frustration using Make later!