The “Andesite Sun” from Sarmizegetusa Regia - the first sundial in Romania -

1. The “Andesite Sun” from Sarmizegetusa Regia - the first sundial in Romania -

2. SARMIZEGETUSA REGIA The great capital of the Dacian state, built in the middle of the first century B. C., was structured in three parts: the fortress, the sacred zone and the civilian settlement.

3. Sarmizegestusa Regia, the capital of Dacia, main political and religious centre was built to defend the whole system of fortifications. Sarmizegetusa was the largest craft center, and its status as political, cultural and religious capital of the Dacian state was a positive factor in the economical prosperity. It was here that kings, officials, officers of the royal chancery, a part of the aristocracy, artisans, merchants, skilled builders, doctors lived. Sarmizegetusa fortress was built on Gradistii hill, the only place with the right configuration in the opinion of the Dacians, at about 1000 m altitude; the fortress walls surrounded the top of the hill.

4. The Sacred Zone All sacred buildings of Sarmizegetusa focus on two large artificial terraces. There are two types of sanctuaries: rectangular and circular. A first phase includes raising limestone buildings and after that, andesite buildings. There are three rectangular sanctuaries, one of which has impressive dimensions, a small circular sanctuary and another square sanctuary. Spectacular is the so called "andesite Sun" - a central disc with a diameter of 1.46 m extended with ten trapezoidal rays, with the exterior edges carved in a bow shape, each 2.76 m long. There is a long ray pointing to the North and stuck to the exterior edge of the altar.

6. The calendar of Sarmizegetusa • Considering Sarmizegetusa, it became obvious for archaeologists and historians that the sanctuaries were used to measure time, a kind of temple calendar. The group consists of two shrines, called the small and the large circular sanctuaries. • The small circular sanctuary consists of 114 pieces, of which 13 are stones which separate groups of 13 columns with the following structure: 8 groups of eight poles, one group of seven poles, three groups of eight poles and a group of six poles. In total, 104 poles and 13 stones. • The big circular temple consists of three concentric circles and an apse construction (closed horseshoe-shaped) located centrally with a symmetry axis and an axis of thresholds. The outer circle consists of 104 blocks of andesite glued to one another, the next circle consists of 210 pieces, of which 30 are stones separating 30 groups of six pillars - a total of 180 poles and 30 stones. The third circle is composed of four groups of four stones that separate groups of columns - a total of 68 poles and 14 stones. The central apse is composed of two groups of stones that separates two groups of poles - a total of 34 poles and four stones.

8. Due to research and calculations, it was discovered that 47 circles in the small sanctuary correspond to 13 astronomical years, after which a correction of one day was needed. It is believed that the Dacians had a calendar based on cycles of 13 years.       The calculations show that the Dacian year had 47 weeks. The small sanctuary is divided into 13 groups, the new year beginning on the first day of a group (a week). All those 13 first days of the 13 groups are only once the beginning of the year within one cycle.         Dacian years had a fixed number of days. Due to the continuous rotation, the fact that each year had 47 weeks and two weeks of exception (only 7 and 6 days, compared to the usual number of eight days), the number of days in a year varied between 364 and 367 days. Following the central apse of the great sanctuary, the researchers concluded that the year was divided into three periods: 13, 21 and again 13 weeks. The two groups of columns contain 13 and 21 pillars. Interestingly, the 21 weeks correspond to the " vegetative period “ of vines and several other crops, a special period of year, for a people of farmers and herders. Considering each stone of the apse as a symbol for the correction in a cycle of 13 years, there results a Dacian period of 52 years (four stones - four corrections, 4 x 13 = 52).

10. The average number of Dacian days in a year is 365.2307692 days, compared to the tropical year of 365.242198 days. The difference between the tropical year and the Dacian one gets to 0.148574 days after a course of 13 years. This difference was corrected, every 8th cycle, that is, after the 104th year. As mentioned, the first circle of the great sanctuary also contains 104 blocks of andesite and represents the time of the correction.       This leads us to the conclusion that the Dacian century had 104 years.      The Dacian calendar has the following main features:       • the equivalent of a pole = 1 day;         • the construction of the small sanctuary causes fluctuating periods of the year, a system that ensure accuracy, using whole units in a cycle of 13 years.       • the year always begins on the first day of the week and ends on the last day       • the error is just one day in 8840 years!

11. Presented by the Comenius team from School 2 Galati, Romania