Jamieson, Fausset and Brown on 1 Thessalonians 5:7

7. This verse is to be taken in the literal sense. Night is the time when sleepers sleep, and drinking men are drunk. To sleep by day would imply great indolence; to be drunken by day, great shamelessness. Now, in a spiritual sense, "we Christians profess to be day people, not night people; therefore our work ought to be day work, not night work; our conduct such as will bear the eye of day, and such has no need of the veil of night" [Edmunds], (1Th 5:8).