The Friendly Enough Expression Language, FEEL, empowers business people to write expressions in a manner that is easy to understand and write.
A duration can be written in ISO 8601 format as P6DT17H6M as a duration of 6 days, 17 hours and 6 minutes.
Using the FEEL functions ceiling and floor it is possible to round up and down this duration into either P7D or P6D.
Notice that "duration" is a reserved keyword and should not be used for activity id.
