Use a lookup table instead:
Find an unused area and enter a table like this:
A Sun 4 6 5 4 4 Sat
B Sun 7 6 5 5 5 Sat
C Sun 7 6 6 6 6 Sat
Select the whole table and Insert-Name-Define and enter a name e.g.
adddays.
Assuming that A1 is the cell where the category is entered, then in B3
enter the formula
=VLOOKUP($A$1,adddays,Weekday(A3)+1)

Or if you don't care what happens to weekends, do it like this:
A 4 6 5 4 4
B 7 6 5 5 5
C 7 6 6 6 6
Select the whole table and Insert-Name-Define and enter a name e.g.
adddays.
Assuming that A1 is the cell where the category is entered, then in B3
enter the formula
=VLOOKUP($A$1,adddays,Weekday(A3))



CTA wrote:

I am trying to write a if then formula based on the category entered
into a cell. There are three categories. Category A, B, & C.

If category A is entered I want the following formula to be executed

=IF((WEEKDAY(A3)=2),A3+4,IF((WEEKDAY(A3)=3),A3+6,I F((WEEKDAY(A3)=4),A3+5,IF((WEEKDAY(A3)=5),A3+4,IF( (WEEKDAY(A3)=6),A3+4,"")))))

If category B is entered I want the following formula to be executed.

=IF((WEEKDAY(A3)=2),A3+7,IF((WEEKDAY(A3)=3),A3+6,I F((WEEKDAY(A3)=4),A3+5,IF((WEEKDAY(A3)=5),A3+5,IF( (WEEKDAY(A3)=6),A3+5,"")))))

If category C is entered I want the following formula to be executed.

=IF((WEEKDAY(A3)=2),A3+7,IF((WEEKDAY(A3)=3),A3+6,I F((WEEKDAY(A3)=4),A3+6,IF((WEEKDAY(A3)=5),A3+6,IF( (WEEKDAY(A3)=6),A3+6,"")))))

How can I accomplish this with excel?