There is a task to calculate how much time has passed from filling one hour field to another. I'm using automation in Jira, but the field I've created isn't getting populated under the right conditions.
{{TimeCandidate}} = {{[Planned Start Date].diff([Planned End Date]).[days]}}
or the new TimeCandidate variable
and in the formula line {{[Planned start date].diff([Planned end date]).[days]}}