Night

Sahih Bukhari
Volume 7, Book 69, Number 527:

Narrated Jabir bin 'Abdullah (radiallaho unho):

Allah's Apostle (salallaho alaihi wasallam) said, "When night falls (or when it is evening), stop your children from going out, for the devils spread out at that time. But when an hour of the night has passed, release them and close the doors and mention Allah's Name, for Satan does not open a closed door. Tie the mouth of your water-skin and mention Allah's Name; cover your containers and utensils and mention Allah's Name. Cover them even by placing something across it, and extinguish your lamps."