I want Excel to prevent me from being able to input a non-working day into a cell OR to be able to place a conditional format on the cell if a non-working day is input.

What I have been able to do is use the WEEKDAY function in the adjacent cell and place a conditonal format on that cell if the nymber is between 6 and 7 however I would prefer the cinditional format to be on the cell where the date is actually input.

Perhaps there is another way other than conditional formats??

Any ideas??