does weekday function work with an array/range?

does weekday function work with an array/range? for me it doesnt! however in the excel class Sidd sir has used the formula: =SUMPRODUCT(--(WEEKDAY(DATE(2023,1,$C$5:$AG$5))=2)*(C6:AG6="A")) to solve a problem from stack exchange. please kindly explain how an array can be input to a function that doesnt take an array for arguement.