Sect (Day & Night Charts)

A foundational Hellenistic distinction: a chart is diurnal (a 'day chart') if the Sun was above the horizon at birth, and nocturnal (a 'night chart') if it was below. Sect shapes how the other planets are read.

Sect is one of the oldest organizing ideas in traditional astrology, and it depends on a single fact: was the Sun above or below the horizon at the moment of birth? Above the horizon (the half of the chart from the Descendant up over the Midheaven to the Ascendant) makes a diurnal, or day, chart; below makes a nocturnal, or night, chart. It needs an accurate birth time, because it hinges on where the horizon fell. The planets are then sorted into two teams. The diurnal team is the Sun, Jupiter, and Saturn; the nocturnal team is the Moon, Venus, and Mars. In a day chart the diurnal planets are 'in sect' and tend to operate more smoothly; in a night chart the nocturnal ones do. The 'sect light' is the leading luminary — the Sun by day, the Moon by night. One practical consequence traditional astrologers lean on: the malefic that is in sect (Saturn by day, Mars by night) usually behaves more constructively than the one contrary to sect. Sect is computed — it is just the Sun's position relative to the horizon. What it is taken to signify is interpretive tradition.

Not: Sect is not a prediction and not a rating of a chart as good or bad. It is a frame that adjusts how the other placements are weighed. It also isn't determinable without a birth time — with the time unknown, this reading omits it rather than guessing.

Which sect a chart belongs to is computed exactly from the birth time. The teams, the 'in-sect malefic behaves better' rule, and the rest are traditional interpretive conventions, not demonstrated effects.