Merriam-Webster Collegiate Dictionary - calendar

 I. noun  Etymology: Middle English calender, from Anglo-French or Medieval Latin; Anglo-French kalender, from Medieval Latin kalendarium, from Latin, moneylender's account book, from kalendae calends  Date: 13th century  1. a system for fixing the beginning, length, and divisions of the civil year and arranging days and longer divisions of time (as weeks and months) in a definite order — see month table  2. a tabular register of days according to a system usually covering one year and referring the days of each month to the days of the week  3. an orderly list: as  a. a list of cases to be tried in court  b. a list of bills or other items reported out of committee for consideration by a legislative assembly  c. a list or schedule of planned events or activities giving dates and details  4. British a university catalog  II. transitive verb  (-dared; ~ing)  Date: 15th century to enter in a ~