There have been several interesting recent threads about NT chronology Jubilee years and the seventy weeks of Daniel.
There certainly was a later understanding that the seventy weeks were fulfilled in 70 CE with the fall of Jerusalem. And if 70 CE was a significant year then 21 CE (one previous Jubilee) would also be a significant year. The problem is that although we have good evidence that 69 or 70 CE was a sabbatical year we have no good early evidence that, before the tragic events of the fall of Jerusalem, it was regarded as a particularly significant sabbatical year, e.g. the end of a Jubilee. The significance given to this year may well postdate the fall of Jerusale.
However we have an interesting interpretation of the seventy weeks of Daniel in the Testament of Levi. From the Testaments of the Twelve Patriarchs.
A major problem is that the Testaments in their present form are a Christian work, (the immediately following section is clearly basically Christian), however Beckwith presents good evidence that the section about the Jubilees is based on pre-Christian material. (Fragments of a Hebrew Testament of Levi related in some way to the version in the Twelve Testaments have been found at Qumran.) Although this does not exclude Christian modification I am going to regard the passage as evidence for a pre-Christian interpretation of Daniel.AND whereas ye have heard concerning the seventy weeks, hear also concerning the priesthood. For in each jubilee there shall be a priesthood.
2 And in the first jubilee, the first who is anointed to the priesthood shall be great, and shall speak to God as to a father.
3 And his priesthood shall be perfect with the Lord, and in the day of his gladness shall he arise for the salvation of the world.
4 In the second jubilee, he that is anointed shall be conceived in the sorrow of beloved ones; and his priesthood shall be honoured and shall be glorified by all.
5 And the third priest shall he taken hold of by sorrow.
6 And the fourth shall be in pain, because unrighteousness shall gather itself against him exceedingly, and all Israel shall hate each one his neighbour.
7 The fifth shall be taken hold of by darkness. Likewise also the sixth and the seventh.
8 And in the seventh shall, be such pollution as I cannot express before men, for they shall know it who do these things.
9 Therefore shall they be taken captive and become a prey, and their land and their substance shall be destroyed.
10 And in the fifth week they shall return to their desolate country, and shall renew the house of the Lord.
11 And in the seventh week shall become priests, who are idolaters, adulterers, lovers of money, proud, lawless, lascivious, abusers of children and beasts.
12 And after their punishment shall have come from the Lord, the priesthood shall fail.
13 Then shall the Lord raise up a new priest.
14 And to him all the words of the Lord shall be revealed; and he shall execute a righteous judgement upon the earth for a multitude of days.
The passage divides the seventy weeks into ten jubillees of 49 years each. The defilement of the temple under Antiochus and the establishment of the (libelled) Maccabean priesthood occur towards the end of the seventh Jubilee. In order to fit the chronology of these events the seventh Jubilee must end somewher around 150-148 BCE with the tenth Jubilee ending around 3-1 BCE. (Probably in the Sabbatical year 2-1 BCE.)
This would make the claim in our current text of Luke that Jesus was about 30 in the 15th year of Tiberius as amounting to a claim that Jesus was born in a sabbatical year. (IF Irenaeus gives evidence of a tradition that Jesus died at age 49 then this would be a claim that Jesus died in a sabbatical year but I'm a bit dubious here.)
This would imply that if Luke is adjusting his account so that events should occur on a significant date, then the significant date involved is the date of Jesus' birth. (The dates of Jesus' ministry may have gone back to pre-Lukan tradition.)
Andrew Criddle