[moon and star.gif]Calendar: Ur



Ur (modern Tell al-Muqayyar) was a Sumerian city in southern Mesopotamia established early in the Ubaid period (c. 4000 BC). The city was the primary center for the worship of the Moon god, Nanna (Sin), and is home to a magnificent ziggurat built for the purpose of his adoration. Ur was a port city for Mesopotamian trade with countries in the Persian Gulf and beyond until the 18th century BC and was probably abandoned in the 4th century BC because of a change in the course of the rivers (Roaf p101).


Tablets from pre-Sargonic (before 2334 BC) Ur give us nine month names, however their order is not known. The names are as follows:

  1. itishe-kin-[ku5]
  2. itiezem-mah-dNin-a-zu5-ka
  3. itiab-gir-gu7-dEn-ki-ka
  4. itine-girx
  5. itiezem-mah-dNanna
  6. itiamar-sag-gu7-dNanna
  7. itia-ki-ti
  8. itishu-esh-dNanna
  9. itiezem-mah-dNin-e-gal


The calender was reformed in the UrIII period by Shulgi, king of Sumer from 2094-2047 BC. Five of the pre-Sargonic month names survived the transition, and the total number of months rose from nine to twelve. The months are as follows:

  1. she-kin-[ku5]
  2. mash-ku-gu7
  3. zahx(SHESH)-da-gu7
  4. u5-bimushen-gu7
  5. ki-sig-dNin-a-zu
  6. ezem-dNin-a-zu
  7. a-ki-ti
  8. ezem-dShul-gi
  9. shu-esh5-sha / ezem-dShu-dSuen
  10. ezem-mah
  11. ezem-an-na
  12. ezem-dMe-ki-gal
  13. iti-diri ezem-dMe-ki-gal


The 13th month is the intercalary month.

One interesting aspect of the UrIII calendar year is that it seems to have been only 6 months long. The New Year festival was celebrated on both the 1st and 7th months. In effect, the year was broken down into two "equinox years", the beginnings of which fell on the vernal and autumnal equinox. There is both astronomical and mythological reasoning behind this, as Cohen explains:

The equinoxes began a period of disharmony between the moon and the sun. During the "equinox year" between the seventh and the first month the moon was visible longer in the skies, the reverse during the other "equinox year." In Ur, the city of the moon, the a-ki-ti was a celebration of the triumph of Nanna, the moon--particularly the a-ki-ti of the seventh month, when Nanna would begin having visible superiority over the sun, Utu. This may be the reason the a-ki-ti of the seventh month at Ur appears to have been more important than that of the first month. (Cohen p141)


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[scorpion with moon and star] A Guide to Ancient Near Eastern Astronomy

Comments Are Very Welcome

Hope Anthony
September 14, 1995