Astrology of sect
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. As can be seen by the example of Mercury, which is more obscured by being occidental, sect is a form of astrological polarity, much as the distinction between masculine and feminine planets. Since some planets were seen to be stronger in a positive or masculine environment, and others were seen to be more effective in a negative or feminine environment, whether a planet is in  sect in any given chart was of particular importance to Hellenistic astrologers, who gave sect greater weight than any other astrological factor. The luminary of sect is the luminary which is said to rule each 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. The planets. "Diurnal" planets are more comfortable and powerful when they  appear in charts in which the Sun is "above" the horizon. They include: "Nocturnal" planets are more comfortable and powerful when they appear in charts in which the Sun is "below" the horizon, or at night. They are: Mercury, a hermaphroditic and very adaptable planet, possesses no inherent sect. Mercury changes its sect orientation depending upon whether it is oriental of the Sun (that is, positioned so that it rises before the Sun rises and sets before the Sun sets), in which case it is "diurnal" in sect; or occidental (that is, rising after the Sun rises and setting after  the Sun sets), in which case it is of "nocturnal" sect. Historical usage. Medieval astrology became even more complex in its treatment of sect – although the factor itself became considerably less important. The Arab astrologers of the Middle Ages defined three forms of sect: Planets satisfying all three of these sect conditions were said to be "Hayz", but it is not clear how Hayz strength compares to strength from essential dignities.