The years and months are artificial, solar, and they reckon the year at 365¼ days exactly. In some astronomical observations, the fraction in excess is less than ¼. According to Ptolemy, it is 14 m. 48 s. The Elkháni observations make the minutes the same, but 32 seconds and 30 thirds. According to the calculations of the Cathayans* the minutes are the same, and 36 seconds, 57 thirds; to the recent Gurgáni observations, the minutes agree, with 33 seconds; the Maghrebi has 12 m.: the Battáni, 13 m. 36 s. Muḥíyu'ddín Maghrebi says that some of the Syro-Macedonian calculations make the fraction more than a quarter, others less than a quarter, and thus a quarter has been taken as the medium. Others assert that the Syro-Macedonians have by observation determined the fraction to be a full ¼. Consequently it is a natural solar year, although Mulla 'Ali Kúshji* makes it a solar year even on the first mentioned basis. This era dates from the death of Alexander the second,* Bicornutus, but was not employed till 12 years after his death. Others assert that he established it in the 7th year of his reign when he set out from Macedonia, his kingdom, bent on foreign conquest. Muḥíyu'ddín Mughrebi on the other hand, states that it began with the reign of Seleucus (Nicator) who founded Antioch.* This era was in use both with the Jews and Syrians. They relate that when Alexander the son of Philip marched from Greece to the conquest of Persia, he passed through Jerusalem. Summoning the learned Jews of Syria he directed them to discontinue the Mosaical era and to employ his own. They thus answered him. “Our forefathers never observed any era above a thousand years and this year our Era will complete the thousand; from next year, there­fore, thy command shall be obeyed.” And they acted accordingly. And this took place in Alexander's 27th year. Some maintain that this Gre­cian era is of Hebrew origin. Kushyár* in his Jámi' says that there is no difference between the Syro-Macedonian and the Syrian era, except in the names of the months. The Syrian year begins on the 1st day of Tishrín ul Awwal. This happened formerly when the sun was in the 4th degree of Libra, and now falls on the 11th.* With the Syro-Macedonians, that date is the 1st of Kánúni i Sáni, when the sun is near the 20th degree of Capricorn. Battáni mentions this era* as beginning with Philip, father of Alexander Bicornutus, but that he called it after his son to exalt his fame; and he has based on it the calculation of the mean places of the planets in his Canon. Of this era 1905 years have elapsed.