Kurdish calendar throughout Kurdistan follow the same principal structure for the "Kurdish days of the week". The Kurdish name for the first day of the week Sheme (Saturday) is in fact descended from Akkadian word Shabattu (In Sumerian Shabbât, Arabic Sabbath, Pahlavic Shunbat, Persian Shambed; Shamba; Shanbeh, even transferred to Greek as Sabbaton, German Samstag, Italian sabato, Spanish sábado, French Samedi). The Akkadian called the 15th day of the month, the day a full moon appears, Shabbattu. The question still remains why such an adoption was made for Kurdish and Persian days of the week. It has been documented that the Babylonian
Determination of the day of the week January 1, 2000. (year − 1 for January) formula_3 formula_4 Note: The first is only for a 00 leap year and the second is for any 00 years. The term mod 7 gives the values of months: The term mod 7 gives the values of years: The term mod 7 gives the values of centuries: Now from the general formula: formula_5; January 1, 2000 can be recalculated as follows: formula_6 formula_7 Kraitchik proposed two methods for calculating the day of the week. One is a graphical method. The other uses a formula that he credits to Gauss on p. 110: