i have to agree with you there, but these are spiritual seasons, and it seems they are being defined in terms of worldly milestones. Maybe it's just me, dunno.
Yes, But these were forms of worship, Physical forms that they did every year, on the same day according to Gods Calendar! 1st they established the maturity of the Barley, and then watched for the New Moon! this established the Head of Months Aviv, on the 10th day of the month they selected a Lamb, on the 14th they Killed the Lamb, and at evening the ate the Passover, and so on. the next new Moon was the beginning of the Next Month, and so on. So these were a practice, one might say, year after year. I think that Stephen called them the Living Oracles, They had the Law, and God said these are MY FEASTS, which you shall proclaim throughout your Generations forever! Jesus fulfilled the Spring Feasts, He interred the city on the young donkey on the 10th of Aviv, and was examined by all on the Temple Mount for four Days, and He was the Lamb of God that was Sacrificed before sundown on the 14th Day, Our Passover Lamb! And He will fulfill the Fall Feasts in every detail that they were rehearsed, or Practiced, this physical form of Worship.