These thirty-six figures are small constellations that become visible on the eastern horizon just before sunrise for a period of ten days. They are called decans, meaning ‘tenths.’ They were used by the ancient Egyptians to mark divisions in the solar calendar. The decans were also very important in ancient Egyptian astrology. Each astrological sign was associated with three decans, ruled over by a planet and given an astrological sign. The decans were also known as star-gods, and were shown in art moving across the sky in boats.