excel if isnumber search

im trying to check cell IF contains a string "Friday" AND the houre is bigger/later then 17:00 THEN multiply the hour rate by 1.5 im using this func:

=IF(ISNUMBER(SEARCH("Saturday",$A$3:$A$33)),$C$40*((C45-B45)*24)*1.5,IF(ISNUMBER(SEARCH("Friday",$A$3:$A$33)),IF("Friday",A42:A71,IF(TIME(17,0,0),$C$40*((C45-B45)*24)*1.5,$C$40*((C45-B45)*24)))))

in short explain is: Everything multyply by $C$40 (25$) except of Friday after 17:00 that its multiply $C$40 *1.5

But its not working for me - can somebody help?