It is the oldest functioning Astronomical Clock in the world dating back all the way to the year 1410. Prague Astronomical Clock was installed in the last decade of the Bohemian Golden Age under the reign of Charles IV. The Astronomical clock show runs every hour sharp from 9 AM till 11 PM.
Prague Astronomical Clock shows four different times known as Old Czech time, planetary hours, sidereal time, and "German" hours. Which one shows the current hours? The latter illustrates the current time since the mid-16th century. "German" hours are marked with 24 golden Roman numerals along the circle of the astrolabe. You can also find old numerals on the outer frame of the clock dial that indicate Old Czech Time counted from the dawn. It was brought from Italy by the Holy Roman Emperor and Bohemian King Charles IV.
See the explanation of how to read the Astronomical clock in our youtube video!
The unique mechanism of the Prague Clock not only shows us what time and day it is, but also tracks the movement of celestial bodies, or planetary hours, like the Sun and Moon. Depending on their position, predictions of upcoming events were made. People would even decide when to receive popular medical treatments such as bloodletting based on that!
The last time system was added in 1865 for astronomical purposes. Sidereal time rotation lasts 23 hours and 56 minutes.
There are also four figurines on the side of the clock dial or astrolabe. They symbolize the allegories of Death, Greed, Lust, and Vanity. The figurines move their heads and hands when the clock rings to signalize every hour from 9 am to 11 pm. They are joined by 12 Apostles and a Golden Rooster whose crow ends the procession and the movement of the allegories. Don't miss the show!
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Author: Valeriia Zahradnikova and Vaclav Zahradnik, Prague guides certified by Prague City Tourism agency. Valeriia and Vaclav have worked in tourism for over 6 years and have guided thousands of Prague visitors.