There never was a fixed time to read Bhagavad Gita.
Reading Bhagavad Gita is not like reading a textbook; we can never understand contents of Bhagavad Gita literally. Bhagavad Gita must always be indulged via path of contemplation (chintan), the only path to understanding jnana wisdom contained in scriptures of different religions of world.
No wonder, how many times people read Bhagavad Gita nothing becomes clear. I receive e-mails from so many people world over that they had read Bhagavad Gita several times but were unable to reach the hidden underlying meaning.
It is apparently clear that none world over wants to indulge in contemplation (chintan). Probably the path is difficult. Finding religious practices (indulgence in rituals) to be easier, all flocked places of religious worship, unmindful of the fact that indulging in religion one gained nothing on path of pure spirituality.
God can be reached only by indulgence in sacred texts of spirituality, never religious scriptures.
One can read Bhagavad Gita any given moment of life. I have indulged in Bhagavad Gita even while walking, talking, jogging, swimming, studying in class and while indulging in business. One can contemplate on vital issues of life contained in Bhagavad Gita any given moment of time. We do not require a specific timeframe for that.
If we can master the delicate art of contemplation (chintan) early in life, we can follow gist of sacred texts of different religions of world like ABCD.