This beautiful sundial dates back to the times of king Jan III. The vertical dial was designed by John Hevelius, the astronomer and Adam Adamandy Kochanski, the royal librarian, in the years of 1681-1682 and is made in stucco in the baroque style. The figure of Chronos is a central point of this triple-dial surrounded by six small putto.
The hand which casts its shadow on the dial is a feather in the right hand of Chronos. The central dial with Roman numerals, the largest of the dials, is the hour clock.
To either side of this, there are images of the zodiac signs. Below, there are mythological symbols of the days of the week; the moon for Monday, the shield of Mars for Tuesday, the caduceus of Mercury for Wednesday, the lightning bolts of Jupiter for Thursday, the mirror of Venus for Friday, the scythe of Saturn for Saturday, and the sun for Sunday.

The dial to the left is the so-called Italian clock. It indicates how much time has passed since the last unset.
To the right, on a Babylonian clock, one can see how much time has passed since the last sunrise.