Prague: Astronomical Clock December 21, 2001 - January 4, 2002 one of the Prague pages on muellerworld [Click here for photos of Old Town Square]

The gold sun follows a circle through the blue part of the clock face during the day, dipping into the black bottom section at night. The arm that has the sun on it points to the hour on the inner ring that has the Roman numerals on it (in this photo, it is noon: XII). The outer ring is Bohemian time (a 24-hour clock, starting from sunset). More about the clock is written here.