The planetary hours are based on an ancient astrological system called the Chaldean Order of the Planets. This is the sequence: Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon, then repeating endlessly Saturn, Jupiter, etc.

The Chaldean Order specifies the relative orbital velocity of the planets. From a heliocentric (Sun-centred) perspective this sequence also indicates the relative distance of the planets from the Sun (with the Sun switching places with the Earth in the sequence) and the distance of the Moon from the Earth. From a traditional geocentric (Earth-centred) perspective the Chaldean Order also shows the arrangement of the planets.

The planetary hours use the Chaldean Order to divide time. Each planetary hour of the planetary day is ruled by a different planet. The planet that rules the first hour of the day (counted from sunrise) is also the ruler of the whole day and gives the day its name. Thus the first hour of Sunday is ruled by the Sun, the first hour of Monday is ruled by the Moon and so on.

Thus, if you wanted to use the energies of a specific planet, the planetary hours can help you choose a day and the time of that day that is best to perform your working.

Table of Planetary Hours