I feel like this should be super simple but I am just not getting it right.
Based on Frequency: Daily, weekly, monthly I want to change the next due date
This will be calulated from Created column and +1, 7, 30 etc added. It works single instance =IF(Frequency@row  = "Daily", Created@row  + 1) but as soon as I try to write it for various  Frequencies it no longer works. 
 =IF(Frequency@row  = "Weekly", Created@row  + 7), IF(Frequency@row  = "Daily", Created@row +1)
    
        
            
    
Not sure if I am over simplifying it or just missing a key step.