Henock 75:1-3
1 And the leaders of the heads of the thousands, who are placed over the whole creation and over all the stars, have also to do with the four intercalary days, being inseparable from their office, according to the reckoning of the year, and these render service on the four days which are not reckoned in the reckoning of the year. 2 And owing to them men go wrong therein, for those luminaries truly render service on the world-stations, one in the first portal, one in the third portal of the heaven, one in the fourth portal, and one in the sixth portal, and the exactness of the year is accomplished through its separate three hundred and sixty-four stations.
MMT A (4Q394 1-2)
I
[On the sixteenth of it (of the second month): sabbath.]
On the twenty-third of it: sabbath.
[On] the thir[tie]th [of it: sabbath.
On the seventh of the third month: sabbath.
On the fourteenth of it: sabbath.
On the fifteenth of it: Feast of Weeks.
On the twenty-] II [f]irs[t] of it: sabbath.
[On] the twenty-eighth of it: sabbath.
The first of the sabbath (=Sunday), and the secon[d da]y (=Monday) [and the third are to be added. And the season is complete: ninety-one days.
The first of the fourth month: Memorial day.
On the fourth] III of it: [sabbath.]
On the e[leventh] of it: sabbath.
On the eighteenth of it: sabbath.
On the twenty-fifth of it: sabbath.
On the second of the fift[h] (month): [sa]bb[ath.
On the third of it: Feast of Wine, first of sabbath (Sunday).]
IV [On the ninth of it: sabbath.]
On the sixteenth of it: sabbath.
On the twenty-third of it: sabbath.
[On the th]irtieth [of it: sabbath.
On the seventh of the sixth (month): sabbath.
On the fourteenth of it: sabbath.
On the twenty-first] V of it: sabbath.
On the twenty-second of it: Feast of Oil, fir[st of sab]bath (Sunday). Af[terwards]: offe[ring of Wood].
4Q394 3-71 i
(19) [The (twenty)-eighth of it (of the twelfth month)]: sabbath.
The first [of the] s[abbath (=Sunday) and the second day (=Monday) and the third are to be ad]ded to it. (20) And the year is complete: three-hundred and si[xty-four] (21) days. vacat
(The Tekufah, the last day of the season, always preceeds a Memorial Day, the 1st day of the season)
(Echad chodesh vs Rosh chodesh)