day book vs written account

day book and written account both are nouns.

Word	Noun	Adjective	Verb	Adverb
day book	Yes	No	No	No
written account	Yes	No	No	No

As nouns, written account is a hypernym of day book; that is, written account is a word with a broader meaning than day book:

day book: the daily written record of events (as arrests) in a police station
written account: a written document preserving knowledge of facts or events

Other hypernyms of day book include written record.

day book (noun)	written account (noun)
the daily written record of events (as arrests) in a police station	a written document preserving knowledge of facts or events