• Perpetual Calendar and Compass
• Brass 
• Perpetual Calendar Covers 40 years from 2004 to 2044
• Height: 0.8 in. (2.06 cm)
• Diameter: 2.95 in. (7.45 cm)

An early, simple perpetual pocket calendar calculator. Its origin goes back some 500 years. Calculate the day of the week for any given future date, within a 40-year span. To use, simply rotate dial until the selected year lines up with the selected month. Locate the particular date and find the day of the week above it.