According to Funk and Wagnall's, a calendar is a "system of measuring time for the needs of regular daily life, by dividing time into days, weeks, months, and years." The Browne Popular Culture Library has a selective collection of all kinds of calendars, from various decades and covering various topics, as seen below.
Last Updated, M. Zuzik, 2/25/06. Updated again by Nancy Down, Summer 2015.
For a detailed inventory of this collection, see the Calendar Collection finding aid.