There are several time offsets which cause different time lines for the rapture and the 70 weeks. I wondered if a 6 month gap between spring and fall feasts mixed into these variables would yield a connection.
I searched for a 6 month period in the bible and found it at the beginning of Esther. 180 days of celebration at the Palace. The first several verses of Ester detail a celebration in the palace of Ahasuerus(Xerxes). Verses 1:4,5 were eye opening; even more so when I looked at the Hebrew. Following is a literal(amateur) translation using the roots of some of the words in the verses.
1:4 He beheld his works' glorious riches, inducted into his kingdom by his costly acts, for fully 180 days.
1:5 When these days were completed, the king made a banquet for all the congregation , delivered into the trumpet palace, great and small, seven days in the trumpet court of the garden of the king's palace.(For reference, trumpet in this verse comes from the term lily, it's shape.)
Time period offsets of 7, 10, 30, 45 and 50 days have been associated with the 70 weeks time line. Working these with the 6 months above might connect the spring to the fall feasts in interesting ways.
If the book of Esther foreshadows the tribulation, then it starts with a great banquet while the king has a gentile bride. Later, He takes a Jewish bride and saves her people from destruction.