Hi, I really need the right formula to add. I have tried several and continue to receive an error. I am able to get =IF(ISNUMBER(a1);WORKDAY(a1;43);"") with no issue but when I add further info to it, ie another IF statement I receive an error. Here is what I am trying to accomplish.

A1 = Referral Date
B1 = Transfer Date
C1 = Referral Due Date
D1 = Transfer Due Date

If A1 is entered then C1 will calculate the due date, via the formula above, B1 and D1 = blank
If A1 & B1 both have dates then D1 should calculate 30 days out and C1 = blank

Also, not really sure if I need to place both if statements in C1 or does it have to be broken into two cells. Please help! Thanks. Sorry haven't worked with excel formulas in too many years.