Planetary hour

The planetary hour, the oldest timing scheme in Western astrology. Each day belongs to a planet and so does each hour, cycling in the Chaldean order (Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon). An hour here is a TWELFTH OF THE DAYLIGHT rather than sixty minutes, so it stretches in summer and shrinks in winter, and the first hour after sunrise always belongs to the day's own ruler. Taking every 24th hour of that cycle is what produced the order of the days of the week. Its Vedic sibling, the hora, walks the same seven planets in the same order but measures each as a flat sixty minutes, so the two can name different rulers for the same moment.