What does the song A Hard Days Night mean?

Answer 1

"A Hard Day's Night," the title of a Beatles song and movie, is a play on the expression "a hard day's work." It suggests that one works in the night (as most bands do) instead of in the daytime.

Answer 2

The story goes that Ringo made the comment after a grueling all night recording session. John liked the play on words, and wrote a song about it. The night was part of the day, so to speak.