TI-Basic, 22 bytes

getDate
identity(1≠dayOfWk(Ans(1),Ans(2),Ans(3

Only works on TI-84+/SE. Assumes that the date is set correctly before the program is run. There is a newline at the end.

TI-Basic, 22 21 bytes

getDate
log(log(dayOfWk(Ans(1),Ans(2),Ans(3

-1 byte by using MarcMush's method but replacing ln( with log(.

Only works on TI-84+/SE. Assumes that the date is set correctly before the program is run. There is a newline at the end.