An early, simple calculator from a time when 50 years was something like eternity. Its origin dates back about 500 years. Calculate the day of the week for any date in the future within 50 years. To use, simply turn the knob until the selected year matches the selected month. Find the date and day of the week above it. Colour: Polished Material: brass Dimensions: LxWxH: 5.5 x 5.5 x 1.1 cm