I am doing a trailhead advance admin exercise on getting the day of the week.
However, the system does not believe it is the correct formula.
Can someone please help?

Here's what I have:

CASE( MOD(TODAY() - DATE(1900, 1, 7), 7),
1, "Monday",
2, "Tuesday",
3,"Wednesday",
4, "Thursday",
5, "Friday",
6, "Saturday",
0, "Sunday",
"")

However, the system gave me the following error:
"Challenge Not yet complete... here's what's wrong: 
The 'Day_of_the_Week__c' is not reporting the correct day of the week (Monday, Tuesday, etc.)"