depending tasks: link task start to other task finish
A good feature would be if a task start can be linked to some other task being finished.
For example, "pay carpenter bill" could be linked to "carpenter repairs veranda" with a "first saturday after 'carpenter repairs veranda' finish" setting.
This way "pay bill" would pop up in my to do list e.g. the next saturday after "carpenter repaired veranda" is checked off, as saturday is the day I have to do all my administrative tasks.
The advantage is, that I can make a complete plan up front without having to check if I have to set new dates for depending taks in between events. (this consumes so much time.)
A second advantage is, that my filter for tasks with no dates set, will exclude all depending tasks. This creates a lot more overview: now it only contains tasks that really dont have a plan date yet, and really need attention in order to get done.