Formula field to find day of the week in Salesforce?

Sample code:

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

Cheers!!!