Provide a way to move the start, due, and reminder dates in one step
Currently, when a task needs to be shifted to a new day, the start, due and reminder dates all need to be changed. It would save some effort if this could be done in a single step - without having to change 3 dates.
Here are some ways this could be implemented:
* As an option for each task, so that the start and reminder dates are stored as an offset from the due date. Whenever the due date changes, the start and reminder dates move as well.
* As a global option, so all tasks store their start and reminder dates as an offset from the due date.
* As a separate command within the task editor, which shifts all three dates by a certain number of days.
Or simply a popup window asking if I want it...