sect
/sɛkt/
The division of the seven traditional planets into two teams, diurnal (day) and nocturnal (night), based on whether the Sun is above or below the horizon at the time of birth. The Sun leads the diurnal sect, and the Moon leads the nocturnal sect.
Sect is one of the most fundamental concepts for evaluating planetary condition in Hellenistic and Medieval astrology. The diurnal sect, led by the Sun, includes Jupiter and Saturn. The nocturnal sect, led by the Moon, includes Venus and Mars. Mercury is considered neutral, joining the diurnal sect when it is a morning star (rising before the Sun) and the nocturnal sect when it is an evening star (setting after the Sun). A planet is strengthened and functions more constructively when it is "in sect"—that is, when a diurnal planet is in a day chart (Sun above the horizon) or a nocturnal planet is in a night chart (Sun below the horizon).
This condition is crucial for moderating the expressions of the benefics and malefics. The "in sect" benefic (Jupiter by day, Venus by night) is considered most constructive, while the "out of sect" malefic (Mars by day, Saturn by night) is considered most destructive. For an astrology student, determining the sect of the chart is a primary step in judging a planet's ability to produce either positive or negative outcomes.