Every day we have to meet with the morning and evening because of the diurnal motion of our planet.
When one side of the earth gets lighten with sunlight, darkness covers the other.This process is continuing from the very first stage of creating the space.Hence every life has been maintaining certain works in a sequence.Like in the evening every animal and birds come back to their residence even the trees also stopped photophosphorilation.As the development of science men invented lights to remove darkness.Here you are seeing one of its example.There are darkness around the house but an electric light is spreading light inside the room.