Yom Teruah  יוֹם תְּרוּעָה

Yom Terua - known as the Day of shouting, Day of blowing, Day of raising a noise, Day of emitting of loud noises and the Day of merriment falls on the first day of the seventh month.

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. (4M 29:1)

Yom Teruah was the beginning of a new agricultural cycle and was a Holy Assembly מִקְרָא קדֶשׁ Mikra Kodesh. All work, except the preparation of food for this feast, is prohibited.

Speak unto the children of Israel, saying: In the seventh month, in the first day of the month, shall be a solemn rest unto you, a memorial proclaimed with the blast of horns, a holy convocation. (3M 23:24)

During Yom Teruah there is special public worship and the specific prayers for this holiday are recited Tefilat Yom Teruah תְּפִלַּת יוֹם תְּרוּעָה. The Ten days from the beginning of the seventh month till the Day of Atonement יוֹם כִּפּוּרִים Yom Kipurim are referred to as the Ten days of repentance עֲשֶׂרֶת יְמֵי רַחֲמִים Aseret yemey rakhamim. Special  prayers Selikhot סְלִיחוֹת were compiled for these days of repentance. On these days worship assembly begins before sunrise because we read prayers of repentance, then after these special prayers we say the usual prayers.