24Speak unto the children of Israel, saying, In the seventh month, in the first day of the month, shall ye have a sabbath, a memorial of blowing of trumpets, an holy convocation.
24 Verse 24. A memorial of blowing of trumpets] This is
generally called the feast of trumpets; and as it took place on
the first day of the seventh month, Tisri, which answers to
September, which month was the commencement of what was called
the civil year, the feast probably had no other design than to
celebrate the commencement of that year, if indeed such a
distinction obtained among the ancient Jews.
See Clarke on Ex 12:2.
Some think creation began at this time.