Rosh Hashanah and Yom Kippur are the two High Holy Days in the Jewish calendar. The term Rosh Hashanah, meaning the Head of the Year, doesn’t occur in the Torah. It appears in Ezekiel Chapter 40 where actually it refers to the Spring season that is Aviv, the original beginning of the Calendar. The Torah defines the holiday in the seventh month simply as Yom Teruah, the festival of the blowing of the shofar, without going into any further explanation.