In the project I'm working on I have created a column called `Project Delivery` `Start Date` and a column called `Delivery Days`. 

I want to use the start date and delivery days to create the Project Delivery Start Date, but need to include the formula 

```
=if([Delivery Days >=6, [Project Start Date]+[Delivery Days]+2, else if(([Delivery Days >=10, [Project Start Date]+[Delivery Days]+4)) 

```

The reason I want this is if the project has 6 delivery days I need to have 2 extra days to cover the weekend, as these dates will be used to create calendar entries later on 

But I keep getting errors