Heaven and earth will pass away, but my words will never pass away.
Now concerning that day and hour no one knows—neither the angels of heaven nor the Son—except the Father alone.
Matthew 24:35-36
I was reading some site and they made some sense (I think).
Jesus did all sorts of miracles or told parable on the various Jewish festivals. The only thing that He hadn’t asn’t included was the Feast of Trumpets.
IIRC it is in the fall. It is a harvest feast iirc. (Recall the numerous parabeles of grain, harvest, sowing, etc.)
The festival begins after some phase of the moon in the fall. And it begins at sunrise - which is determined by two witnesses showing up at the temple to confirm it. Cloud cover, etc. will make that time variable - and it needs to be confirmed by a second person.
So the exact time that the festival starts is not known by anybody. Excep GOD).