Perpetual calendar

. A calendar that can be used perpetually or over a wide range of years. That of Capt. Herschel covers, as given below, dates from 1750 to 1961 only, but is capable of indefinite extension.

To find the day of the week corresponding to any date, find the small letter directly under the month and opposite the day of the month; the same small letter also appears in the vertical column that contains the number of the year, and if the line in which it stands is followed out to the right, the day of the week is found. Thus, the small letter under March and opposite 18 is b; b appears again directly over 1904, and at its right is the word Friday. March 18 fell on Friday in 1904, and also in 1898, 1892, etc. The calendar has other uses, as for finding the months which begin on Sunday in a particular year, etc.

|1753 |1754 |1755 |1750 |1751 |1757 |*1752
 |1759 |1765 |*1760 |1761 |*1756 |1763 |1758
 |*1764 |1771 |1766 |1767 |1762 |*1768 |1769
 |1770 |*1776 |1777 |*1772 |1773 |1774 |1775