Ōmagatoki
Ōmagatoki is a Japanese term referring to the moment at dusk when the sky grows dark. The opposite of, yūrei, and dark creatures"; and second, "the time of great calamity".
In Illustrated One Hundred Demons from the Present and the Past, Toriyama Sekien described ōmagatoki as the time when chimimōryō, the evil spirits of the mountains and rivers, attempt to materialize in the world.
