Use our free Planetary Hours and Days Calculator to quickly find the ruling planet for any specific hour, date, and location. Understand the ancient system of planetary timekeeping and align your activities with celestial energies.
Formula:
The calculation of planetary hours traditionally involves determining the precise times of local sunrise and sunset. The period from sunrise to sunset (day) is divided into 12 equal 'day hours', and the period from sunset to the following sunrise (night) is divided into 12 equal 'night hours'.
The sequence of ruling planets follows the Chaldean order: Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon. The first planetary hour of the day (starting at sunrise) is ruled by the planet associated with that day (e.g., Sunday by the Sun, Monday by the Moon). Subsequent hours follow the Chaldean order.
Simplified conceptual steps:
- 1. Determine Day Ruler: Based on the input Date (e.g., Sunday = Sun, Monday = Moon).
- 2. Calculate Hour Lengths:
Day Hour Length = (Local Sunset Time - Local Sunrise Time) / 12, andNight Hour Length = (Next Local Sunrise Time - Local Sunset Time) / 12. - 3. Assign Hour Rulers: Starting from the day's ruler at sunrise, cycle through the Chaldean order for each subsequent hour.