What are planetary hours and how do I use them?

## Direct Answer Planetary hours constitute a traditional astrological system that apportions the 24-hour day into twelve diurnal (daylight) and twelve nocturnal (nighttime) periods. Each of these segments is governed by one of the seven classical planets: Saturn, Jupiter, Mars, Sun, Venus, Mercury, and the Moon. The sequence of these planetary rulers follows the traditional Chaldean order (Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon). The primary purpose of identifying planetary hours is to determine auspicious moments for engaging in particular activities, especially those of a magical or spiritual nature, by harmonizing the practitioner's intent with the sympathetic influence of the ruling planet. ## Historical & Doctrinal Context The concept of planetary hours emerged from the intricate tapestry of Hellenistic astrology and Neoplatonic philosophy, finding extensive application within Medieval and Renaissance ceremonial magic. The assignment of planetary rulership to hours is predicated on the Chaldean order of the planets, which arranges them by their apparent speed and distance from Earth in geocentric cosmology: Saturn (slowest, outermost), Jupiter, Mars, Sun, Venus, Mercury, Moon (fastest, innermost). This order is crucial for determining the sequence of planetary hours and the planetary ruler of the day itself. Ancient sources, such as Vettius Valens' *Anthology* (2nd century CE), detail the intricate calculations and significance of planetary positions. Later, influential grimoires and treatises, including the *Picatrix* (Ghayat al-Hakim, 11th century CE) and Agrippa von Nettesheim's *Three Books of Occult Philosophy* (1531), provided comprehensive instructions on calculating and utilizing planetary hours for magical operations. These texts emphasize the Neoplatonic understanding of a divinely ordered cosmos, where celestial bodies exert specific, benevolent influences that can be intelligently engaged through appropriate timing and ritual. The underlying principle is one of 'sympathy' or 'correspondence,' where terrestrial actions resonate with celestial archetypes. Proclus, in his *Elements of Theology* and commentaries on Plato, articulated the Neoplatonic view of a hierarchical cosmos imbued with divine intelligences. The planets, in this view, are not mere material bodies but are ensouled by divine agencies, acting as intermediaries between the divine One and the material world. Engaging with planetary influences thus becomes a form of theurgy, a co-creative act with these divine intelligences. ## How It Works Calculating planetary hours is distinct from standard clock hours because they are not fixed increments. Instead, both day and night are divided into twelve equal parts, meaning that the length of a planetary hour changes with the seasons and geographical location. ### Calculation Method 1. **Determine Sunrise and Sunset:** Accurate local sunrise and sunset times are essential. These vary significantly throughout the year and by latitude. 2. **Calculate Day Length:** Subtract sunrise time from sunset time. Divide this duration by 12 to find the length of one diurnal planetary hour. 3. **Calculate Night Length:** Subtract sunset time from sunrise time of the following day. Divide this duration by 12 to find the length of one nocturnal planetary hour. ### Planetary Sequence The first hour of any day is ruled by the planet after which the day is named (e.g., Sunday's first hour is ruled by the Sun, Monday's by the Moon, Tuesday's by Mars, etc.). Subsequent hours follow the Chaldean order. For instance, on a Sunday: * 1st hour: Sun * 2nd hour: Venus * 3rd hour: Mercury * 4th hour: Moon * 5th hour: Saturn * 6th hour: Jupiter * 7th hour: Mars * 8th hour: Sun (the cycle repeats every 7 hours) This sequence continues throughout the 24 hours (12 day hours, 12 night hours), ensuring that the first hour of the next day begins with its corresponding planet. This continuous cycle ensures a systematic rotation of planetary influences throughout the week. ## Practical Application Practitioners utilize planetary hours to align their spiritual and magical operations with the specific energetic qualities of the planets. This involves selecting the appropriate planetary hour for the desired outcome, thereby enhancing the sympathetic resonance of the working. For instance: * **Sun Hours:** Favorable for operations concerning authority, leadership, fame, success, healing, and general well-being. Suitable for works of [illumination](/answers/illumination) or seeking favor from those in power. * **Moon Hours:** Ideal for workings related to dreams, divination, psychic development, emotional matters, fertility, domestic affairs, and contacting lunar intelligences. Often employed in [scrying](/answers/scrying) or visionary practices. * **Mars Hours:** Best for operations requiring courage, strength, protection against adversaries, banishing, warding, and vigorous action. Also useful for works of defense or breaking negative influences. * **Mercury Hours:** Propitious for communication, study, learning, writing, commerce, magical theory, and divination. Excellent for intellectual pursuits or crafting [magical sigils](/compendium/sigils). * **Jupiter Hours:** Beneficial for matters of prosperity, abundance, legal success, honor, expansion, and spiritual wisdom. Used for attracting wealth, good fortune, and benevolence. * **Venus Hours:** Suited for operations involving love, friendship, reconciliation, beauty, art, pleasure, and artistic endeavors. Also effective for attracting harmony and affection. * **Saturn Hours:** Grave hours, often used for operations involving bindings, limitation, protection from harm, introspection, deep meditation, or dealings with elders and ancestral spirits. Some practitioners also use Saturn hours for works of [exorcism](/answers/exorcism) or banishing. By carefully selecting the hour of a specific planet, the practitioner seeks to draw upon and integrate th