Hi everyone

I would like to subtract 1 day from a date field, and store the result in another date field. I want to use this in a calendar view. I tried to use a calculated value field in my list, but the calendar view does not seem to accept columns which are calculated values. 

So, my next bet is to do the calculation in the workflow. In my calendar view, I need the "startdate"  and the "enddate". But the end date is "Returndate" - 1. The result must be a date only value.

Can someone assist me with the syntax and the type of action to use inside the workflow?