i have about 4 date cells. in 3 of the cell a date has to be entered but
depending on which cell the date is entered the due date will be diffrent.

|-------------------------------------------------------|
| cell1 | cell2 | cell3 | cell4 | cell5 | due date |
|-------------------------------------------------------|
| 90day|1year|2year|30day|60day| due date |
|-------------------------------------------------------|
| 90day|1year|2year|30day|60day| due date |