“What is night for all beings is the time of awakening for the self-controlled; and the time of awakening for all beings is night for the introspective sage.” BG 2.6
It could be said that any time of the day is the best time of the day for connecting with transcendence – remembering you are not this body, and meditating on the sweet love of the soul that is the essence of Krishna consciousness. However, when Prabhupada was asked what is the best time for chanting japa, meditating on Krishna’s na