Jubilees 6:30-38

30 And all the yamim of the commandment will be fifty two weeks of yamim and these will make the entire year complete. So it is engraved and ordained on the heavenly tablets.

31 And there is no neglecting this commandment for a single year from year to year; no year can have thirteen chodashem or more than fifty two weeks.

32 And command the children of Yisrael that they observe the years according to this reckoning, three hundred and sixty four yamim and these will constitute a complete year and they will not disturb its time from its yamim and from its moadem; le olam va-ed will take place in them according to their testimony and they will not leave out any yom nor disturb any moadem.

33 But if they do neglect and do not observe them according to His commandment, then they will disturb all their moadem and the years will be dislodged from this order and they will disturb the moadem and the years will be dislodged and they will neglect their ordinances.

34 And all the children of Yisrael will forget and will not find the derech of the years and will forget the new chodashem and moadem and the Shabbats and they will go wrong as to all the order of the years.

35 For I know and from now on will I declare it to you and it is not of my own devising; for the scroll is written before me and on the heavenly tablets the division of yamim is ordained, lest they forget the moadem of the brit and walk according to the moadem of the goyim after their error and after their ignorance.

36 For there will be those who will assuredly make observations of the yarayach - how it disturbs the moadem and comes in from year to year ten yamim too soon.

37 For this reason the years will come upon them when they will disturb the order and make an abominable yom, the yom of testimony and an unclean yom a moed yom and they will confound all the yamim, the kadosh with the unclean and the unclean yom with the kadosh; for they will go wrong as to the chodashem and Shabbats and moadem and Yovleem.

38 For this reason I command and testify to you that you may testify to them; for after your death your children will disturb them, so that they will not make the year three hundred and sixty-four yamim only and for this reason they will go wrong as to the new chodashem and moadem and Shabbats and moadem and they will eat all kinds of dahm with all kinds of flesh.