New word: Calendarsthenics

n. 1. Mental exercise involving figuring dates or times, including adding or subtracting hours and figuring the weekday on which a certain date falls (past, present or future); 2. Scheduling a meeting or other get-together with others who have busy schedules; 3. Attempting to revise common concepts of time or historical milestones to conform to new or different values, i.e. counting years in other-than-C.M.E. or A.D. time.