Planetary Hour
Planetary hours provide a practical, granular timing tool for aligning daily activities with supportive planetary energies. Unlike sign ingresses or transits that operate over days or months, planetary hours allow practitioners to select the most auspicious hour of any given day for starting a specific type of activity. The system remains one of the most actionable traditional techniques for electional purposes, requiring only sunrise time and a basic calculation to implement in everyday decision-making.
Definition
Planetary hours are an ancient system that divides each day and night into twelve unequal temporal segments, assigning each segment to the governance of one of the seven classical planets in a rotating sequence. The hours of the day are counted from sunrise to sunset and divided into twelve equal parts, while the night hours run from sunset to sunrise, also divided into twelve equal parts. Because days and nights vary in length throughout the year, planetary hours are almost never sixty minutes long except at the equinoxes. The planet governing the first hour of the day also gives that day its name: the hour of the Sun rules the first hour of Sunday, the Moon rules Monday, Mars rules Tuesday, Mercury Wednesday, Jupiter Thursday, Venus Friday, and Saturn Saturday. The sequence continues through the day and night in the Chaldean order — Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon — cycling through all seven planets repeatedly until the next sunrise. Planetary hours were widely used in electional astrology for timing mundane activities: the hour of Venus for love and aesthetic pursuits, the hour of Jupiter for legal matters and wealth, the hour of Mars for surgery or competitive endeavors. Medical astrologers used planetary hours to time the administration of treatments. The system appears in Ptolemy, medieval Arabic texts, and Renaissance magical texts alike.
Worked Example
A surgeon choosing between two possible times for an elective procedure might consult planetary hours and avoid scheduling during the hour of Mars — traditionally associated with cutting, blood, and the risk of inflammation — particularly on a Tuesday when Mars governs the entire day. Scheduling instead during the hour of Jupiter or the Moon on a day with supportive planetary conditions represents the electional principle of using time quality as a factor in outcome optimization, a practice endorsed by most major medieval medical authorities.
Looking up charts?
A professional astrologer can read these placements in your natal chart and explain what they mean for your life.
Consult an AstrologerFirst 5 Minutes Free