eve vs twenty-four hours

eve and twenty-four hours both are nouns.

Word	Noun	Adjective	Verb	Adverb
eve	Yes	No	No	No
twenty-four hours	Yes	No	No	No

As nouns, twenty-four hours is a hypernym of eve; that is, twenty-four hours is a word with a broader meaning than eve:

Other hypernyms of eve include 24-hour interval, day, mean solar day, solar day, twenty-four hour period.

eve (noun)	twenty-four hours (noun)
the latter part of the day (the period of decreasing daylight from late afternoon until nightfall)	time for Earth to make a complete rotation on its axis
the day before
the period immediately before something