daybreak vs break of the day

daybreak and break of the day both are nouns.

Word	Noun	Adjective	Verb	Adverb
daybreak	Yes	No	No	No
break of the day	Yes	No	No	No

As nouns, daybreak and break of the day are synonyms defined as:

Other synonyms of daybreak include aurora, break of day, cockcrow, dawn, dawning, dayspring, first light, morning, sunrise, sunup.

daybreak (noun)	break of the day (noun)
the first light of day	the first light of day