UNDERSTAND THE METHOD
Day, night and the meaning of sect
Sect distinguishes a chart with the Sun above the horizon from one with the Sun below it. The seven formulas here reverse between those two conditions.
Go deeper: the full reference
Use the Sun and the local horizon
In this calculation, day and night refer to the Sun’s position at the birth instant and place. They are not determined by the clock hour, the season, daylight-saving time or a general impression of whether the sky was bright. A chart can be a night chart while twilight is visible.
The convention used by this calculator
Synastry uses the geometric altitude of the Sun’s center relative to the local horizon: at or above 0° is day; below 0° is night. The calculation does not add atmospheric refraction, the Sun’s apparent radius or an elevation correction. Visible sunrise and sunset can therefore differ from this mathematical boundary.
A paired example
Using Ascendant 100°, Sun 40° and Moon 170°, the day formula for Fortune gives 230° and the night formula gives 330°. Spirit gives the complementary result: 330° by day and 230° by night. This example compares formulas; a real chart’s sect must come from its Sun and horizon.
When the Sun is close to rising or setting
The calculator flags a Sun-center altitude within 1° of the horizon. Around that boundary, a small time change or a different horizon convention may change the selected sect and several Lot positions. Review the recorded time and the stated method before treating a boundary result as settled.
What this label does not say
Day and night are calculation categories, not rankings of a person’s worth, strength or prospects. The traditional doctrine of sect is broader than this formula switch. For this tool, begin by understanding which formula was applied and why.
Follow the Lots in your own chart
Use your recorded birth time and birthplace to calculate the seven Hermetic Lots. Compare the stated sect and formulas with this lesson, then read each placement as a symbolic question in its chart context.
Method and context
These references support the historical context and the Paulus formula convention. Interpretations and reflection questions are original Synastry work.
The Astrology Podcast: The Lot of Fortune and Spirit in Astrology ↗ · Historical discussion of Lots, the Paulus scheme and differences between authors such as Paulus and Valens.
Arabic parts: The Hermetic lots ↗ · A secondary reference table for the seven day and night formulas attributed to Paulus Alexandrinus.
Al-Biruni: The Book of Instruction in the Elements of the Art of Astrology ↗ · R. Ramsay Wright translation, §475–476: Fortune and the Sun’s Lot (Spirit). The latter is given more fully as the Lot of the unseen and religion; names and formulas vary across authors.
Arabic names of the zodiac signs ↗ · Arabic-language reference for the familiar twelve zodiac signs. These labels do not define a separate zodiac or change the calculation.
Arabic zodiac vocabulary and transliteration ↗ · Arabic zodiac terms. We consistently write the article al-; its pronunciation can assimilate to the following consonant.
Unicode: Lot of Fortune ↗ · U+1F774 LOT OF FORTUNE (pars fortunae), cross-referenced with U+2297 ⊗. Synastry uses the familiar crossed-circle vector form.
Connect the ideas
What are Arabic Parts?
Arabic Parts, also called Lots, are calculated zodiac points. Their formulas connect the Ascendant with relationships between other chart positions.
2 min readArabic names and symbols
Learn the Arabic names of the twelve zodiac signs, the historical names of Fortune and Spirit, and how to distinguish a Lot symbol from an associated planet.
2 min readRead a Lot formula and follow the degrees
Convert each position to a longitude from 0° to 360°, apply the stated formula and wrap the answer around the zodiac.
2 min readWhy birth time and birthplace matter
Every Lot here uses the Ascendant, which depends strongly on the birth instant and location. An uncertain time should remain visible in your interpretation.
2 min read