Duration without requiring start or end date
When determining when to start or end my tasks it would be extremely helpful to already have the duration of the task. Then when I decide what date to start it, the end date is calculated based on the duration and the newly added start date or vice versa, add the end date and the start date is calculated. Without losing the current functionality of adding a start date or end date and the duration to calculate the other date respectively. My acceptance criteria for this would be:
Allow adding of duration without needing start or end date
Allow changing of duration without needing start or end date
Allow adding a start date to a task with a duration existing and end date is calculated.
Allow adding an end date to a task with a duration existing and start date is calculated.
Do not break existing functionality.