The Talmud (Rosh Hashana 11a) discusses why “Eisanim” – which means “mighty ones” – is the Biblical name for the month of Tishrei. Rabbi Eliezer says it is because the Avos – Avraham, Yitzchak and Yaakov – were born in that month. Rabbi Yehoshua says it’s because the month is made mighty through the many mitzvos of Rosh Hashana, Yom Kippur and Succos.