Jubilees 15:1-4
[1]And in the fifth year of the fourth week of this jubilee, [1979 A.M.] in the third month, in the middle of the month, Abram celebrated the feast of the first-fruits of the grain harvest.
[2]And he offered new offerings on the altar, the first-fruits of the produce, unto Yahuah, an heifer and a goat and a sheep on the altar as a burnt sacrifice unto the Lord; their fruit offerings and their drink offerings he offered upon the altar with frankincense.
[3]And Yahuah appeared to Abram, and said unto him: 'I am God Almighty [El Shaddai]; approve thyself before me and be thou perfect.
[4]And I will make My covenant between Me and thee, and I will multiply thee exceedingly.'

Jubilees 16:13
[13]And she bare a son in the third month, and in the middle of the month, at the time of which Yahuah had spoken to Abraham, on the festival of the first fruits of the harvest, Isaac was born.

Jubilees 28:15
[15]And again Jacob went in unto her, and she conceived, and bare him a fourth son, and he called his name Judah, on the fifteenth of the third month, in the first year of the fourth week. [2129 A.M.]