WordNet (r) 3.0 (2006):

day book
    n 1: the daily written record of events (as arrests) in a police
         station [syn: blotter, day book, police blotter, rap
         sheet, charge sheet]

Bouvier's Law Dictionary, Revised 6th Ed (1856):

DAY BOOK, mer. law. An account book, in which merchants and others make
entries of their daily transactions. This is generally a book of original
entries, and as such may be given in evidence to prove the sale and
delivery, of merchandise or of work done.