Planetary hours

Calculations run in this browser with Astronomy Engine 2.1.19 (MIT license). Times use the selected IANA zone or a documented UTC offset. For ancient records, a modern city zone does not establish the historical clock convention. Gregorian and Julian dates are explicit; output dates and the lunar calendar use Gregorian. There is no modern-era date cutoff, but accepting a distant date is not a guarantee of modern-era precision.

City names, coordinates and time zones derive from GeoNames, under CC BY 4.0. Dataset notice. City input is resolved locally, and is neither saved nor sent to a location service.

The conventional order is Saturn, Jupiter, Mars, Sun, Venus, Mercury and Moon. The weekday ruler starts the first hour at sunrise; twelve hours divide the daylight and twelve divide the following night. This convention is described in The Key of Solomon, book I, chapter II. It is separate from the astronomical calculation and does not assert that an hour guarantees an outcome.

Sunrise and sunset use the Sun’s upper limb and the engine’s standard atmospheric refraction at sea level, with an unobstructed horizon. Weather and terrain can shift observed times. A full ordinary daily cycle is required; polar day or night cannot be divided this way.