/ Dictionary / Index C calendar day: Meaning and Definition of Find definitions for: cal'endar day' Pronunciation: [key] the period from one midnight to the following midnight. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. calendar clock calendar month Related Content Daily Word Quiz: apogee Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language