Extracted with some editing from an early article on the Kurdish calendar from Wikipedia.
Background At about the time of the conquest of Babylonia by Cyrus, the kings of Persia made the Babylonian cyclic calendar (months, weeks, days) standard throughout the Persian Empire, which at the time comprised Kurdistan as well. The Seleucids, and afterwards the Parthian, and Sasanian rulers of Iran maintained the Babylonian calendar until the Arab conquest in AD 621. The Arabs introduced the Muslim lunar year, but the Persians continued to use the solar year of 365 days, which in 1079 was made equal to the Julian year by the introduction of the leap year.
The Kurdish name for the first day of the week Sheme (Saturday) is descended from the word Shabbatu, a Sabbath. The following days get a digit prefix to mark the first, second, third, fourth and fifth days after Sheme (Saturday). The last day of the week is Heynî or Jume (Friday) which is a free day of work for many cultures in Mideast. "None, relax" make the best English explanations for Heynî in Kurdish. Jume, Jivîn, Jemîn and Jemu (gathering or jamboree) are words that have survived in Iran's languages. For more efficiency on using the Kurdish name for the days of a week on Internet these abbreviations are suggested as Sh (Şem.), Ye (Yekşem.), Du (Duşem.), Sê (Sêşem.), Ca (Çarşem.), Pê (Pêncşem.), and În (Înî).
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