It is very important for the believer to study the biblical festivals. Jesus, Yeshua, fulfilled some in His first coming and He will fulfill the rest with His second coming.
The bible does not call them feasts of the Jews or feasts of the Christians, it says they are Feasts of the Lord.
Leviticus 23:4 These are the feasts of the Lord, even holy convocations, which ye shall proclaim in their seasons.
The biblical festival of Yom Teruah/Festival of Trumpets, also known to many as Rosh HaShana starts soon , it is the biblical new year.
Here is a great site to get a calendar , as it is not the same every year:
In light of this, I am sharing a few links for your personal study of this “Festival of Trumpets”.