Bhagavad Gita is a scriptural text gist of which cannot be understood simply by reading. One has to indulge in contemplation (chintan) to reach the hidden underlying meaning.
Following path of jnana yoga (absolute wisdom) is a prerequisite to understanding Bhagavad Gita. During present era the Kali Yuga, indulging in bhakti yoga and karma yoga alone does not make a human being reach state of enlightenment.
The darkness of ignorance can be cut only by indulging in jnana yoga via contemplation (chintan).
Bhagavad Gita is a spiritual compendium that explains vital details of life from origin of cosmos to the end when dissolution of entire cosmos occurs (Pralaya in Hinduism). Bhagavad Gita also tells us that we are primarily a spiritual traveler, a cosmic being undertaking earthly journey.
As a spirit, the consciousness within we manifest human form to cleanse self of dross impurities within. By itself no soul atman, the spirit can purify itself. It needs a medium, a body to work out its karma and reach state of absolute purity.
For human beings to reach cosmic end of life, to emancipate forever from cycle of birth and death, teachings of spirituality contained in Bhagavad Gita are necessitated.
As we can never indulge in Bhagavad Gita literally but only through contemplation, we can indulge in Bhagavad Gita any given moment of life.
I started my spiritual journey six years of age. I indulged in teachings of Bhagavad Gita even while walking, jogging, swimming, studying and indulging in sports and also while conducting business. I could indulge in contemplation any given moment of life.
My primary goal of life from six years of age was reaching God, emancipation from cycle of birth and death forever. Do not know how I mastered art of contemplation when six years of age. Maybe everything flowed from my last manifestation.
Bhagavad Gita is never about reading at night but I truly indulged in Bhagavad Gita even in night-time. When going to bed in the night I laid in shavasna pose of yoga. Thereafter I indulged in pranayama, self enquiry and also Neti (not this, not this) something preached and practiced by Maharshi Ramana. All I wanted to do was dissolve queries within.
By this time I had realized that if all queries within dissolved to zero, I would reach state of Nirvikalpa samadhi (absolute nothingness) when not a single thought entered our brain uninvoked.
I practically indulged in teachings of Bhagavad Gita 24 hours even in daytime and also night.