Night.
Used symbolically for:
1. Death, a time "when no man can work." John 9:4.
2. The moral darkness of the world, in which men sleep and are drunken. 1 Thessalonians 5:7.
3. The period of Christ's rejection, which is far spent, and the 'day' at hand. Romans 13:12. There will be no night of moral or spiritual darkness in the heavenly Jerusalem. Revelation 21:25; Revelation 22:5.