Isha Yoga CenterMahashivratri is one of the largest and most significant among the sacred festival nights of India. This – the darkest night of the year – celebrates the Grace of Shiva, who is considered the Adi Guru or the First Guru, from whom the yogic tradition originates. The planetary positions on this night are such that there is a powerful natural upsurge of energy in the human system. It is enormously beneficial for one’s physical and spiritual wellbeing to stay awake and aware in a vertical position throughout the night.