I'm using Version 2.56.1+161118 and have created a date question which has the Minimum date set to "+20 days". The pop-up calendar works properly and only allows you to select starting 20 days from now. However, if you select the minimum date as your answer, you get "Answer must be between 14/06/2017 and 20/07/2017" (based on today). I'm using the date format dd/mm/yyyy.