A deadline can be set based on data. You can enter a deadline as a date and get a deadline for that specific date. The deadline expression
(DeadlineDate – now) + P7D
gives you the deadline.
When we simulate we can set the startdate to November 1st, 2019 and enter a deadline of December 23rd. 2019, and then the user executed the Set deadline activity. The resulting deadline is December 30rd, 2019, as it is December 23rd, 2019 plus 7 days.