day book vs blotter

day book and blotter both are nouns.

Word	Noun	Adjective	Verb	Adverb
day book	Yes	No	No	No
blotter	Yes	No	No	No

As nouns, day book and blotter are synonyms defined as:

day book and blotter: the daily written record of events (as arrests) in a police station

Other synonyms of day book include charge sheet, police blotter, rap sheet.

day book (noun)	blotter (noun)
the daily written record of events (as arrests) in a police station	the daily written record of events (as arrests) in a police station
	absorbent paper used to dry ink