356 ÉTIENNE NODET above, points to a calendar problem in both cases, and not to a problem in the details of the rites. According to CD 10 :14-17, all work should be interrupted on Friday before sunset, which is not a dissident view, but in 3:12-16 it is said that the Sabbath belongs to the “hidden things” (twrtsn), implying that, from time to time, a week was longer by one day, according to some calendrical decision, or secret computing. An obscure passage of 1 Enoch can be understood this way: in 74:12 we read “the sun and the stars bring in all the year exactly, so that they do not advance or delay their position by a single day”. This shows that there was a corrective system, which worked. However, the next chapter (75:1) speaks of “the four days which are not reckoned in the reckoning of the year”, which have been understood as the four 91st day at the end of the four quarters 17, causing an error of four days every year and awkward problems for the Festival calendar 18, The contradiction between the two chapters is blatant: it seems that a translator or a copyist has mixed up these days with some additional days fixing the solar year. Another hint is given in Jubilees 50 :1-5 : the Jubilee falls on the 50th year, after the seventh sabbatical year, and then a new cycle begins. So the rhythm of the seventh years is broken. Whatever the intercalation system used, both calendars match every 28 years (in average, because of possible lunar leap years). The solar calendar has worked, at least for some time, and rabbinic tradition displays some knowledge of it. There is a “Blessing of the Sun” every 28 years, when the equinox falls on a Tuesday at sunset, recalling the Creation week 19 (b.Erubin 56a). This view depends on an interpretation of that week according to the A Qumran collection of Psalms mentions a special song for the μy[wgp 17 days. S TALMON, “The Covenanters’ Annuarium in the Psalm Scroll from Cave 11 (11QPsa XXVII) ”, Fifty Years of Dead Sea Scroll Research (eds. G. BRIN – B. NITZAN) (Jerusalem 2002) 204-219. See R.H. CHARLES, The Book of Enoch (London 1892) 159-161, who 18 observes that the Ethiopian text is corrupted, and thinks that the author strove to compare that calendar with the Greek 8-year cycle. The date is calculated according to the years of 365.25 days (Julian 19 calendar). So the calculated equinox moves ahead of the astral one by about 3 days every 400 years (the Gregorian correction: the solar year lasts about 365.2468 days). The most recent blessing was performed on April 6th, 2009, that is 17 days after the real equinox.