This is the first time keeping device , with the remains of Egyptian obelisk's date back to 5,000 B.C. The first documented Sundial's were made by the Egyptians in 800 B.C. and were made of green schist. This Sundial has has the quote from Shakespeare, from the play Macbeth " Life is just a walking shadow ". This Sundial is also adjustable for Daylight savings' time with a notch at the bottom that rotates the dial one hour!!!
Such a simple time keeping device!!