Hour: Literally or Figuratively; Watch Vigilantly

When the word "hour" appears in the New Testament, is a literal or figurative hour meant, or does it depend on when it is used?

Verses used in this study:
John 1:35-39,29
John 4:6,52,53
John 11:9
John 4:21-26
John 20:30,31
John 5:25,28,29
Revelation 20:4,5
Matthew 24:42-47
1 Thessalonians 5:4-6