Hello :), 

I'm trying to establish the payment terms of my clients into my invoice in order to have the due date calculated automatically. Could someone explained the kind of fields and formula I should use to have this work. I was hoping to have a choice field to record all the potential payments terms I can have with my clients. 

Also some of my client have very specific payment terms such as: 'End of the current month plus 45 days" or "15 days at the end of the month". I was wondering which kind of formula I will need to set up to get to this result. 

Many thanks :)