Currid notes that, This is the most sacred and most festive month in the Hebrew calendar.
1 As such, the day was announced with trumpet blasts, an activity that is usually for the purpose of assembling people for a major event (Psalm 81:3). On this occasion, the day is to be marked by rest in addition to the offerings mentioned in Numbers 29:1–6.
24 “Speak to the people of Israel, saying, In the seventh month, on the first day of the month, you shall observe a day of solemn rest, a memorial proclaimed with blast of trumpets, a holy convocation.