wee hours

wee hours pl (plural only)

1. The very early morning; the early morning hours; the nighttime hours following midnight, when most people are asleep.
   • 2011 March 15, Tom Armstrong, Marvin (comic):

     When I was young, I was up every night until the wee hours. Now I'm up every hour at night to wee.

Within the context of a sentence, almost always used with the definite article "the", especially, or a demonstrative adjective.

• (very early morning): small hours, wee small hours; see also Thesaurus:early morning