Date object problem in ML

Question

ThE PROBLEM SEEM TO HAVE A BUG
2020-05-12 (2020 MAY 12) IS A TUESDAY AS PER CALENDAR.
BUT SOLOLEARN EXPECTS A FRIDAY.

SIMILARLY SOLOLEARN GIVES AN EXAMPLE wHERE 1993-07-12 iS SHOWN TO BE THURSDAYBUT CALENDAR SHOWS MONDAY FOR 1993 JULY 12

WHAT AM I MISSING

https://sololearn.com/coach/641/?ref=app