Calendars of Priestly Courses

Qumran, Cave 4, fragment 4Q320

The information below is contained in The Complete Dead Sea Scrolls in Englis  by Geza Vermes, page 347

Synopsis

Twelve documents found in cave 4, dated in the second century BCE, present a ‘peculiar’ calendar that combines the priestly courses that served in turn at the Temple a week-at-a-time from one Sabbath to the following sixth day (Friday), while also listing the full moon dates on the solar month and the lunar month. The amazing thing is those events correspond to a modern day Gregorian or moon phase calendar.

Fragment 1 i

I…to show it from the east. [And] to cause it to shine [in] the middle of heaven, in the foundation [of the creat]ion, from evening till morning.

(There is full moon)

On the 4th (day) in the week [of the sons of G]amul in the first month of [the firs]t year. 

[On the 5th (day) in (the week of) Jedai]ah, (corresponding) to the 29th (day of the lunar month, which falls) on the 30th (day) of the 1st (solar month).

The Barley Festival, mentioned in l.4 is elsewhere called the Waving of the Omer.