Astronomical Clock

Overview

The Astronomical Clock of Strasbourg Cathedral is a Renaissance masterpiece of horology — a room-sized mechanical clock that calculates ecclesiastical computations, displays planetary orbits, and performs an automated procession of carved figures daily at 12:30.

Highlights

• The Procession: At 12:30, carved apostles parade past Christ while a rooster crows three times and Death strikes the hours.
• The Computus: The clock calculates the dates of movable feasts (Easter, Pentecost) — a function that will remain accurate until 9999 AD.
• Planetary Mechanisms: Dials display the positions of the known planets, eclipses, and the precession of the equinoxes.

History

The current clock, built between 1838 and 1843 by Jean-Baptiste Schwilgué, is the third astronomical clock on this site. It replaced a 16th-century clock whose carved case and paintings survive. Schwilgué's computus mechanism was a groundbreaking achievement in mechanical calculation.

Visitor Tips

• Timed Entry: A separate ticket is required for the 12:30 show — buy it early from the cathedral shop and arrive by 12:00.
• Don't Be Late: The procession lasts only a few minutes and cannot be repeated.
• Duration: 20–30 minutes.