The 1st of the month of Ethanim holidays now known as Tishrei is Rosh Hashanah and this holiday is also known as the Feast of Trumpets. The term Rosh Hashanah never appears in the Torah where it is dubbed Zikhron Teru'ah or Yom Teru'ah, literally a day of sounding the Shofar. It begins on the 1st day of the 7th month and is the first of the High-Holy Days. It is a New Year's celebration because it is the first month on the sabbatical calendar.
There is no mention in scripture of Rosh Hashanah in the narratives of the year of the dedication of Solomon’s Temple and shortly we will examine conclusive proof that Israel did not observe the High Holy Day of Rosh Hashanah in that year.
A day of blowing the horn unto you...
The Feast of Trumpets
Numbers 29:1 And in the seventh month, on the first day of the month, ye shall have a holy convocation: ye shall do no manner of servile work; it is a day of blowing the horn unto you. 2 And ye shall prepare a burnt-offering for a sweet savour unto the Lord: one young bullock, one ram, seven he-lambs of the first year without blemish; 3 and their meal-offering, fine flour mingled with oil, three tenth parts for the bullock, two tenth part for the ram, 4 and one tenth part for every lamb of the seven lambs; 5 and one he-goat for a sin-offering, to make atonement for you; 6 beside the burnt-offering of the new moon, and the meal-offering thereof, and the continual burnt-offering and the meal-offering thereof, and their drink-offerings, according unto their ordinance, for a sweet savour, an offering made by fire unto the Lord. (JPS)