Calculating a date with Formula

Hello to all, Here is the problem.
I have ‘End-Date’, I have ‘number of production days’ and I would like to calculate the ‘Start-date’ using these two variables. Looking for advice. Kindest regards.

Hi Alain and welcome to the infinity community!
I would use the Workday formula, but with a negative number of days for that, but that´s not possible yet. You better contact the chat support, they might know a working solution. If not, they will forward it to the dev team.

WORKDAY
Syntax: WORKDAY(start_date, num_days, [holidays])
Explanation: Calculates the end date after a specified number of working days.