raags and when they are to be sung

This is one of the sessions I had with Baba when I clarified my doubts on raags.
Me - Baba, I hear that in this system, raags are seasonal and also have a specified time in a day when they should ideally be sung. Why is it so?
Baba ponders over it. Trying to see how best this could be explained.
Baba- Do you like it when you are woken up from your deep sleep in the middle of the night?
Me- Not at all.
Baba- Raags are also like us. They have life in them. They also have their own specific nature. They do not like to be disturbed outside their routine. They are at their best when sung at the right time.

He then went on to explain how the raags get divided around the the time of the day in a very simple manner.
The day gets divided into 8 parts.
at dawn Re1 and Ma1 work best.
then pre noon Re2 and Ma1
afternoon till dusk Re2 and Ma2 combination
after sunset - Re1 and Ma2
Early night Re2 and Ma2
Late night slowly Komal gandhar starts coming into the picture with Re2 and Ma2
Then Komal gandhar with Re2 and Ma1
As it starts coming close to dawn again the Re will change from 2 to 1 with Komal Gandhar.
Its amazing how he could just tackle this question so simply while I kept searching books and net to understand how to differentiate and know when a particular raag is to be sung.

the is a generic classification Apart from this there are many other factors that influence the nature of a raag and exceptions are always there.