24-hour interval vs eve

24-hour interval and eve both are nouns.

Word	Noun	Adjective	Verb	Adverb
24-hour interval	Yes	No	No	No
eve	Yes	No	No	No

As nouns, eve is a hyponym of 24-hour interval; that is, eve is a word with a more specific, narrower meaning than 24-hour interval:

Other hyponyms of 24-hour interval include tomorrow, today, yesterday, morrow, date, day of the month, date, snow day.

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