Planetary Days and Hours for Spellwork

The planetary days and hours system is a timing framework from Western ceremonial magick that aligns specific periods of each day and week with the seven classical planets of ancient astronomy: Saturn, Jupiter, Mars, the Sun, Venus, Mercury, and the Moon. By casting a spell during the day and hour ruled by the planet whose energy corresponds to your intention, you are said to work in alignment with a current of celestial power that amplifies and supports your purpose.

The elegance of the system lies in its double precision. The day of the week gives a broad planetary alignment; the hour within that day refines it. A love spell cast on Friday (Venus) during the Venus hour is considered optimally timed. A working for communication and clarity cast on Wednesday (Mercury) during the Mercury hour carries the same alignment at the hour level.

History and origins

The system has roots in Hellenistic astrology and the astrological lore of ancient Babylon and Egypt. The assignment of days of the week to planets appears in Roman sources from the first century CE and was transmitted into medieval European magic through Arabic astrological texts and the Latin grimoire tradition. Key grimoires including the Key of Solomon, the Picatrix, and the Heptameron include detailed tables of planetary days and hours as essential preparation for ritual operations.

Medieval and Renaissance magicians used planetary timing for everything from healing preparations to conjurations and astrological talismans. The system was considered as practically necessary as having the right materials, since performing a working out of planetary alignment was thought to diminish or misdirect it.

The Golden Dawn and subsequent ceremonial traditions preserved and systematized planetary hours in the nineteenth and twentieth centuries. Contemporary practitioners encounter the system both through grimoire revival work and through eclectic witchcraft resources that incorporate it as a layer of timing refinement.

Magickal uses

Each planet governs a specific domain of human life, and workings in that domain benefit from the corresponding planetary timing.

Sunday (Sun): healing, vitality, success, leadership, solar energy, clarity, and workings related to authority and confidence.

Monday (Moon): intuition, dreams, psychic work, emotions, the home, women”s concerns, water, and workings involving change or cycles.

Tuesday (Mars): courage, protection, conflict resolution, legal matters involving defense, strength, and workings where assertive or martial energy is needed.

Wednesday (Mercury): communication, writing, travel, commerce, learning, trickery, and workings for skill, memory, or negotiation.

Thursday (Jupiter): abundance, expansion, prosperity, luck, higher education, law (for favor rather than defense), and workings for growth in any area of life.

Friday (Venus): love, beauty, pleasure, art, harmony, attraction, sexuality, and workings for relationships, social ease, or sensory enjoyment.

Saturday (Saturn): boundaries, banishing, protection through structure, endings, ancestor work, long-term planning, bindings, and workings aimed at restriction or removal.

How to work with it

Begin by identifying the planetary correspondence for your intention. Then locate the next day of the week ruled by that planet. If urgency demands you work sooner, find the planetary hour of your desired planet on the day available.

Calculate planetary hours using one of the widely available apps (Lunarium and Planetary Hours Alarm are commonly used) or a paper calculation: divide the day (sunrise to sunset) into twelve equal portions and the night (sunset to next sunrise) into twelve equal portions. These are your “hours,” which will be longer or shorter than sixty minutes depending on the season and your latitude. The first hour of the day belongs to the ruling planet of that day; subsequent hours follow the Chaldean order, cycling through all seven planets in sequence and repeating.

Set up your working space at the start of the planetary hour. Many practitioners light a candle in the color associated with the planet: yellow or gold for the Sun, silver or white for the Moon, red for Mars, orange or yellow for Mercury, green or copper for Venus, blue or purple for Jupiter, and black or dark purple for Saturn.

State your intention and complete your working within that hour if possible. If the working runs long, trust that the alignment established at the opening carries through. Many practitioners note the planetary hour in their magickal journal alongside the working’s intention and outcome, building over time a personal record of how the timing affects their results.

In myth and popular culture

The planetary hours system has a literary presence across many centuries of Western writing. Medieval European astrologers and physicians used planetary hours to schedule everything from bloodletting to the administration of herbal remedies, a practice described in the medical writings of Marsilio Ficino and in popular almanacs printed across Europe from the fifteenth century onward. The physician and magician Paracelsus explicitly linked the timing of medicinal preparations to the ruling planet of the hour.

In Renaissance fiction, particularly in works influenced by Neoplatonic philosophy and astrology, characters consult planetary hours before taking significant action. John Lyly’s play “Endymion” (1588) and Thomas Nashe’s “The Unfortunate Traveller” both reflect a culture in which astrological timing was a practical concern for educated readers. William Lilly, the seventeenth-century English astrologer who wrote “Christian Astrology” (1647), one of the most comprehensive English-language astrological texts ever written, included extensive instructions on planetary hours for timing both practical matters and magical operations.

The grimoire tradition preserves the planetary hours as a central practical framework. The Key of Solomon specifies planetary hours for each operation. The Heptameron, attributed to Pietro d’Abano, is organized entirely around planetary hours and days, providing specific prayers, names, and incenses for each combination. These texts have remained in print and circulation through the occult revival of the nineteenth century and into contemporary practice.

In modern fiction, planetary hours appear in the Rivers of London series by Ben Aaronovitch, whose character Thomas Nightingale uses traditional European magical timing frameworks including planetary hours. The broader urban fantasy genre has adopted astrological timing as a recognizable signal of sophisticated magical practice, contrasted with less precise or intuitive approaches.

Myths and facts

Practitioners and curious readers encounter several recurring misunderstandings about the planetary hours system.

• A common belief holds that planetary hours are equal to sixty-minute clock hours, divided evenly through the day. They are not: planetary hours divide the actual daylight and nighttime periods into twelve parts each, making their length depend on the season and latitude, and a summer daytime hour may be ninety minutes long while a winter nighttime hour may be forty minutes.
• Some sources suggest that only the day’s ruling planet is effective during a given day, and that its hours are the only ones worth using. In practice the tradition prescribes using any planet’s hour on any day; a Venus hour on a Tuesday is still a Venus hour, even within a Martian day.
• It is frequently stated that you need specialized software or apps to calculate planetary hours. While apps make the calculation easier, the method is straightforward arithmetic requiring only your local sunrise and sunset times, both freely available from weather services and almanacs.
• Some practitioners believe the planetary hours originated with medieval Christian astrology. The system in fact predates Christianity and is documented in Hellenistic sources from the first and second centuries CE, with probable roots in Babylonian astronomical practice.
• A widespread assumption holds that planetary hours are only relevant to ceremonial or high magic. In fact the system appears in Hoodoo, Appalachian folk magic, and other American folk traditions, where timing workings to the appropriate planetary hour is a common piece of practical advice.