Sect is an ancient astrological concept in which the seven traditional "planets" (including the Sun, the Moon and the five starry planets) are assigned to two different categories: diurnal or nocturnal sect. The Sun is the luminary of sect in a day chart (where the Sun is above the horizon) and the Moon is the luminary of sect in a night chart (when the Sun is below the horizon.) This distinction was crucial in determining the location of the astrological Lots--especially in Hellenistic astrology.