There is no reliable time frames. We have a saying. If you have seen one head injury, you have seen "one" head injury. They are all different. The recovery times are spread out along a bell curve just like many statistical situations are.

'Rest a little bit' is about as good as it gets. They just do not know how to properly describe what 'rest' means regarding concussions. Read the Vitamins sticky at the top like I suggested yesterday and Jo*Mar suggested.