The changing shadows cast upon the ground as the sun apparently moved across the sky have caught people's attention since ancient times. This phenomenon was utilized in planning the sundial, the first tool that allowed people to measure the passing of time and determine the precise time for purposes of work and ritual.
The simplest type of sundial consists of a vertical rod (gnomon) that casts a shadow onto a dial marked with semicircular lines. Over time, sundials were improved and their precision was enhanced. Sundials are referenced in world literature as far back as the Bible. Kings II 20:11 describes the sign presented by the prophet Isaiah to King Hezekiah as proof of the veracity of his prophecy about the defeat of the Assyrian army: "And He made the shadow which had descended on the dial of Ahaz recede ten steps". Researchers believe that the sundial referred to in the Bible as "the dial of Ahaz", which was probably built during the reign of King Ahaz (742-727 BCE), consisted of a wall that cast a shadow during the morning hours onto a flight of stairs built to the west of it.
The Jewish Quarter, Jerusalem
In the early 1970's, a mobile sundial made of stone was discovered among the ruins of a grand building that was unearthed in an archeological dig in the eastern part of the Jewish Quarter of the Old City of Jerusalem after the Six Day War and given the name "Belt Hamidot" (the measurement house). The dial was approximately 11 cms tall and the elegant etchings along its sides attest t o the fact that vv a s a prestigious item used in a wealthy home in the 1st century. The top of the concave scale of dates was fitted with a horizontal bronze rod, which in biblical terminology was called the "sundial nail" (Tractate Kelim 12:5). The stamp features a computerized restoration of the sundial, based on a photo by Pini Hamo.
Al Jezzar Mosque, Acre
One of the most beautiful sundials in Israel was built in 1786 in the courtyard of the Al Jezzar Mosque in Acre. The decorated marble scale of dates is 78 cms long and 50 cms wide. It is a polar sundial, in which the scale of dates is affixed at a 33 degree angle to the ground, in accordance with the geographic latitude of Acre, and the top of the scale faces toward the pole. A dedication is carved into the front of the dial — "This sundial of the Al Anwar Al Ahmedi Mosque, which was dedicated by the honorable, renowned and magnificent minister Hag Ahmed Pasha Al Jezzar, who shall be rewarded by the forgiving God, is dedicated to benefiting humanity. It was built by Ibrahim AI-Faradi the Kurd in 1201 of the hijra of the prophet".
Zoharei Chama Synagogue, Jerusalem
In 1908 a large perpendicular sundial was built on the southern wall of the Zoharei Chama synagogue on Jaffa Street in Jerusalem. It was designed and constructed by Moshe Shapira, a Jewish man from the old Yishuv who was born in the Meah She'arim neighborhood. He learned how to make sundials from Aryeh Leib Gordon, a learned educator in Jerusalem at that time, and from studying a book by the Vilna Gaon. The scale of dates is five meters in diameter and marked with lines indicating 5 minute intervals. The pole that casts the shadow is fixed at an angle, parallel to the earth's axis. Two regular clocks were installed alongside the sundial, one set to European time and the other to "Eretz Israel time".