I would like to set a milestone (given date from external) and then calculate back when I hav to start. So I want a task of 20d start 20 working days before the milestone. This would mean I want to put a SF dependency to the taks. If I do so Wrike automatically changes this to a FF dependency.
The problem with FF is that it will allo the task to shift behind the milestone - exactly what I do not want.
The other way around (the milestone with FF) would not fit to my needs.
Any idea how I can make a task starting for sure 20d before a milestone?