Jewish New Year came early this year. Every year it falls on a different date because the holidays are based on the 10 month Jewish Calendar. It begins on the Jewish Calendar in the 7th month, Tishrei, which typically falls in September or October on the Gregorian calendar. It is believed to have begun as far back as 6th century BC. Ever wonder what to say on Rosh Hashanah, the Jewish New Year, when you meet a Jewish person? The Jewish New Year is not just about vowing new goals to lose weight or work out at the gym.