All the parts of the clock together are 18 meters (59 feet) high. The clock shows much more than the official time; it also indicates solar time, the day of the week (each represented by a god of mythology), the month, the year, the sign of the zodiac, the phase of the moon, and the position of several planets. The lower part of the massive base of the clock has statues of Apollo and the Goddess Diana presenting a circular calendar of the liturgical year, whose revolving face with a globe points to the dates of major religious festivals and events. This part of the clock is surrounded by painted figures representing the ancient empires – Greece, Assyria, Persia, and Rome.
The level above displays a group of mechanical chariots, with allegorical figures representing the days of the week, which move daily to bring to the front the current day of the week. Figures of two reclining women hold a cadran (dial or clock face) between them which tells the minutes.
Above this level is a celestial globe in a sky of painted stars which makes a complete revolution every 23 hours, fifty-six minutes, and four seconds. As it turns, it shows the 1,022 stars identified by Ptolemy, as viewed above the horizon of Strasbourg.
The central tower is composed of three levels. On the bottom, figures of the Four Seasons surround a mechanical astrolabe, which indicates the location of the planets according to Copernicus, and is surrounded by the signs of the zodiac. Above this is a globe, with painted figures of the Church and the Antichrist confronting each other. This mechanism displays the phases of the moon. Above this are two levels of animated mechanical figures, above that a figure of Christ and the four Evangelists, under a dome formed by crossed arches.
Animated characters launch into movement at different hours of the day. One angel sounds the bell while a second turns over an hourglass. Different characters, representing the ages of life (from a child to an old man) parade in front of Death. On the last level are the Apostles, passing in front of Christ. All these automata are put into operation daily at 12:30 pm except Sundays.
Source - wikipedia.com; see the mechanics here: