A few authors have pointed out scattered evidence of certain astronomical associations in some of the ancient Egyptian game boards. This article studies data to sustain that the ancient Egyptian slab, known as 59-hole board, is not a game, as it has been interpreted, but an astronomical instrument to register solar and lunar cycles. The number and the disposition of the holes, the spiritual-astronomical symbolism of the iconography at the boards, the correspondence of the marks at the orifices with the days of the main Egyptian festivities, the parallelisms between the registering system of the slab and the later Greek and Roman calendars known as parapegmata, offer evidences to maintain that the 59-hole board was a calendrical tool for the lunar-solar synchronism. After the Greek and Roman calendars with holes were in use, a different version of the 59-hole original board appeared in Egypt during the sixth century.
