Buddha took 6 years. Nisargadatta Maharaj took 3 years. To attain self-realization.
But, both did not have the same complete intellectual understanding that I have at present when they started their spiritual journey.
So, there is a good possibility I can “know” within the next 3 months also.
But, since unlike them, my spiritual journey has been going on for the last nearly 50 years (I started listening to Swami Chinmayananda’s lectures when I was 12 years old) one could say it took me 50 years to attain self-realization should I attain it within a year if not 3 months.
And, the astrologer who predicted most things about my life pretty accurately when I met him when I was 43 years old also predicted that I will be able to meditate properly only after 60 and indeed get enlightened after 60 (see the screenshot image).
But, as Advaita points out, and as is easily understood intellectually, the truth is that the only enlightenment one can have is that one was never ignorant and was only imagining that one was ignorant. Everyone in this world is already enlightened, but everyone is “imagining” that they are not enlightened yet. The pot is already and always was clay, and the pot is unreal and only a name-and-form, which appears to the sense organ of eye. The wave is already and always was water, and the wave is unreal and only a name-and-form, which appears to the sense organ of eye. Similarly, this world, including all the bodies-and-minds in it, is already and always was Consciousness/God, and the world is unreal and only names-and-forms, which appears to the five sense organs of eye, ear, nose, tongue and touch. Meditate on that.
Know Thyself 