It is the first of the High Holy Days (יָמִים נוֹרָאִים‎, Yāmīm Nōrāʾīm, 'Days of Awe"), as specified by Leviticus 23:23–25,[1] that occur in the late summer/early autumn of the Northern Hemisphere.

Rosh Hashanah is a two-day observance and celebration that begins on the first day of Tishrei, which is the seventh month of the ecclesiastical year.

In contrast to the ecclesiastical lunar new year on the first day of the first month Nisan, the spring Passover month which marks Israel's exodus from Egypt, Rosh Hashanah marks the beginning of the civil year, according to the teachings of Judaism, and is the traditional anniversary of the creation of Adam and Eve, the first man and woman according to the Hebrew Bible, as well as the initiation of humanity's role in God's world.

Rosh Hashanah customs include sounding the shofar (a hollowed-out ram's horn), as prescribed in the Torah, following the prescription of the Hebrew Bible to "raise a noise" on Yom Teruah.

[2] Other rabbinical customs include the "tashlich", attending synagogue services and reciting special liturgy about teshuva, as well as enjoying festive meals.

Leviticus 23:24[5] refers to the festival of the first day of the seventh month as zikhron teru'ah ("a memorial of blowing [of horns]").

[6] The term rosh hashanah appears once in the Bible (Ezekiel 40:1),[7] where it has a different meaning: either generally the time of the "beginning of the year", or possibly a reference to Yom Kippur,[8] or to the month of Nisan.

[13] Semitic speakers generally set the beginning of the new year in autumn, while other ancient civilizations chose spring for that purpose, such as the Persians or Greeks or Hindus; the primary reason was agricultural in both cases, the time of sowing the seed and bringing in the harvest.

According to the Mishnah, four different New Years are observed: Rosh Hashanah (the first of Tishrei), the first of Nisan (when the Exodus began), the first of Elul, and Tu BiShvat (the fifteenth of Shevat).

Elul corresponds to the Gregorian August/September, after the spring birthings, when it was relatively simple to count the number of animals in herds.

Shevat corresponds to the Gregorian January/February, the end of the Mediterranean wet season when the majority of the year's rainfall had occurred.

Taking fruit or nuts from a tree younger than three years old, with the birthday counted as Tu Bishvat, was prohibited.

The intermediate class is allowed a respite of ten days, until Yom Kippur, to reflect, repent, and become righteous;[22] the wicked are "blotted out of the book of the living forever.

The best-known ritual of Rosh Hashanah is the blowing of the shofar, a musical instrument made from an animal horn.

The shofar is blown at various points during the Rosh Hashanah prayers, and it is customary in most communities to have a total of 100 blasts on each day.

[27] While the blowing of the shofar is a Biblical statute, it is also a symbolic "wake-up call", stirring Jews to mend their ways and repent.

In the Ashkenazic rite, Avinu Malkeinu is never recited on Shabbat (except in Ne'ila on Yom Kippur), and it is also omitted at Mincha on Fridays.

The narrative in the Book of Genesis describing the announcement of Isaac's birth and his subsequent birth[33] is part of the Torah readings in synagogues on the first day of Rosh Hashanah, and the narrative of the sacrifice and binding of Isaac[34] is read in synagogue on the second day of Rosh Hashanah.

[44] Rosh Hashanah meals usually include apples dipped in honey to symbolize a sweet new year;[45] this is a late medieval Ashkenazi addition.

[49] Some of the symbolic foods eaten are dates, black-eyed peas, leeks, spinach, and gourd, all of which are mentioned in the Talmud:[50] "Let a man be accustomed to eat on New Year's Day gourds (קרא), and fenugreek (רוביא),[51] leeks (כרתי), beet [leaves] (סילקא), and dates (תמרי)."

Sliced carrots are also typically eaten to symbolize gold coins and hopes for continued wealth and prosperity.

Nowadays, lekach (honey cake) and gefilte fish are commonly served by Ashkenazic Jews on this holiday.

[55] The formal Sephardic greeting is Tizku Leshanim Rabbot ("may you merit many years"),[57] to which the answer is Ne'imot VeTovot ("pleasant and good ones"); while in Ladino, they say אנייאדה בואינה, דולסי אי אליגרי "anyada buena, dulse i alegre" ("may you have a good, sweet and happy New Year").

[citation needed] A more formal greeting commonly used among religiously observant Jews is Ketivah VaChatimah Tovah (Hebrew: כְּתִיבָה וַחֲתִימָה טוֹבָה‎), which translates as "A good inscription and sealing [in the Book of Life]",[55] or L'shanah tovah tikatevu v'techatemu meaning "May you be inscribed and sealed for a good year".

[58] After Rosh Hashanah ends, the greeting is changed to G'mar chatimah tovah (Hebrew: גמר חתימה טובה‎) meaning "A good final sealing", until Yom Kippur.

[55] After Yom Kippur is over, until Hoshana Rabbah, as Sukkot ends, the greeting is Gmar Tov (Hebrew: גְּמָר טוֹב‎), "a good conclusion".

[8] Nonetheless, there is some evidence that Rosh Hashanah was celebrated on a single day in Israel as late as the thirteenth century CE.

[65] Originally, the date of Rosh Hashanah was determined based on observation of the new moon ("molad"), and thus could fall on any day of the week.

[68] The connection between the date of Rosh Hashanah and the memory of the Hamas-led attack on Israel on 7 October 2023 has been noted, for example by the British Chief Rabbi.