Rosh Hashanah, the Jewish New Year, always falls on the first and second day of the Hebrew month of Tishrei. The words “Rosh Hashanah” literally mean “the beginning/head of the year”.
Although it is seen as a festival, Rosh Hashanah is also regarded as an important and solemn occasion. In Jewish thought, it is seen as being the time when all the people of the world – Jewish and non-Jewish – are judged for their actions over the previous year, and their reward or punishment designated
https://www.thejc.com/judaism/features/what-is-rosh-hashanah-1.444107