What Is Perpetual Calendar. If the newspaper is dated january 9, 1899 and states a person died the previous thursday, use the perpetual calendar to find thursday's date. Look through the table below and find the number located to the right of any year between 1801 and 2100.
The perpetual calendar is a very complicated movement. It is perpetual because it automatically adjusts to months with 30 days and to the 28 or 29 days in february.