The Eight Awakenings of Great Beings is from the Shobogenzo by Dogen. The version we are looking at is from the edition published by Shambhala and edited by Kazuaki Tanahashi. You can purchase a copy here.
Ango is a time of increased focus on our vow to fully Awaken for the sake of all beings. Intensification of our zazen, Buddhist practice and participation in the life of the sangha has its roots in the earliest gatherings of the Buddha's disciples. During the rainy seasons in India some 2,600 years ago, mendicant followers of the Buddha would seek shelter in caves for 90 days, and there they would practice and study together with their teacher. Along with Zen communities across the world we continue a modern incarnation of this ancient tradition at the Great Heartland Buddhst Temple of Toledo.