Hi john.

Was pondering.

If the tribulation is 7 years and finishes at the end of the feast of tabernacles. 

Then surely a likely time for the rapture is tabernacles exactly 7 years before!

So i looked to see if tabernacles has trumpets and according to this link it has 3 lots of 7 trumpets which mimic the 3 lots of 7 judgements in revelation.

Though this link does not believe in a pre trib rapture but has interesting comments on the trumpets.

https://messianic-revolution.com/l23-32-sukkots-21-trumpet-blasts-linked-21-judgements-revelations/

21 trumpet blasts that occur during SUKKOT (Feast of Tabernacles) 

John

PS

Another last trump in october

Leviticus 25:9 KJV

Then shalt thou cause the trumpet of the jubilee to sound on the tenth day of the seventh month, in the day of atonement shall ye make the trumpet sound throughout all your land.