On the eastern wall of the town hall tower is a 24-hour sundial made in the 16th century. It was the only clock in a public space in Biecz. The sgraffito technique was used to make the clock's dial, which measures 4 metres in diameter and is very well preserved, constituting a great rarity among historical objects of this kind. The clock operated until 1598; later, it was deemed unnecessary, probably because construction began on a new clock with a 12-hour dial. The 24-hour clock was repeatedly repaired and survived until the 1903 city fire, when it was completely destroyed.