Just read Can We Know the Day? post started by Robbie, and also some interesting points made by Watching and Waiting.
If the rapture were to occur on Rosh Hashanah it would be an astounding sign that would provoke the Jewish unbelievers and Israel to extreme Jealousy of the Gentiles! And they would be Jealous of what they just missed, and would be hungry for God in a desperate way.
The sign given to them will be the sign of Jonah, resurrection, rapture, but it would be too late for them at that time.
The Rapture occurs on a day no man knoweth, ie code for Rosha Hashana.
We all know the two witnesses in Revelation. Those same two witnesses are needed during Rosh Hashannah to witness that event for the Jewish people!
What is required? 2 witnesses! 2 witnesses are needed to view the new moon.
The literal 2 witnesses will "witness" the rapture on Rosh Hashana, and see the Church (wise virgins) are GONE. With the bridegroom.
This could be the event, followed by two witnesses, that cause the Jewish people to repent and cry out for a rebuilding of their temple to attempt to be "grafted" back into their original olive tree again, after being pruned away for their unbelief, which made room for the gentiles.
God could use these events, occurring on these exact feast days, to be a witness for the Jews again for their salvation during the time of Jacobs trouble. God will speak to them through their own festivals.
So this could literally mean the 2 witnesses are alive to see the rapture and are converted to believers at this time (if they aren't already believers in Yeshua) They then begin to witness to Israel as a result of what has happened on Rosh Hashannah! And this has been a festival/feast that they have practiced all this time, but were blinded to the true meaning. As a result they missed the blessing due to their unbelief. Another reason to watch on Rosh Hashannah.