i am trying to set up a workflow that pushes out an email reminder at different times before such official "due date", e.g., 6 months out, 3 months out, etc. I have a few different fields set up in my list to pull dates from, like date of filing and next due date.  the next due date is the date that the reminders are leading up to, e.g., next due date is 2/18/2017, the reminder will be 6 months before that date, 3 months before, etc.  leading up to the date. 

when i put in the calculate date button and put in the info, is  there a way to put in the date of either the filing date or next due date so that the time calculates off of that instead of today's date?