Custom Script
Add an HTML Widget BEFORE the Form with this custom script to manage a personalized “dd.mm.yyyy” date format
NOTE: If no custom Date Format is forced you can use a single line solution directly into the Set Value field:
new Date( new Date([field id="from"]).getTime()+(5*24*60*60*1000)).toISOString().split('T')[0]
Set Value
Add this rule on Fields Conditions with Value:
=format_date([field id="from"])