[Q] What's the best behavior of recurring tasks (to-do)?

Currently I am working on a tasks app (xda thread), and going to implement some recurring tasks function. Because my app sync with Google Tasks (which do not support recurring tasks now) I want to stay compatible with it.

Which is the preferred behavior?

1. Create a new task after current task is complete
2. When mark as completed, auto-mark it as uncompleted and update the due time
3. When mark as completed, mark task as unchangeable (or hide the task like GTasks) until this due date, do the same as above at this due date

I can image situations for each of the three model to be useful, what is your opinion?