Event Planning: Creating a template of tasks with automated due dates based on an event date.

Hi! 

My team has used Asana to create templates for different categories of events that auto-populate tasks with due dates (e.g. 45 days before event date). What is the best method to creating similar templates in Airtable? 

Below is a screenshot from the Asana template. 

I’m looking to get each Due Date cell to auto to x days before the event date, excluding weekends. I tried using DATEADD, but this does not work on individual cells. 

Thanks!