The celebration of the New Month of Cheshvan starts at sunset on Sunday, October 18th
On the calendar:
Shabbat Shuva 2020 / שַׁבָּת שׁוּבָה 5781
Shabbat Shuva (Shabbat that falls between Rosh Hashanah and Yom Kippur (Shabbat of Returning)) for Hebrew Year 5781 begins at sundown on Friday, 25 September 2020 and ends at nightfall on Saturday, 26 September 2020.
Shabbat Shuvah ("Sabbath [of] Return" שבת שובה) refers to the Shabbat that occurs during the Ten Days of Repentance between Rosh Hashanah and Yom Kippur. Only one Shabbat can occur between these dates. This Shabbat is named after the first word of the Haftarah (Hosea 14:2-10) and literally means "Return!" It is perhaps a play on, but not to be confused with, the word Teshuvah (the word for repentance).
Yom Kippur / יוֹם כִּפּוּר
Yom Kippur (Hebrew: יוֹם כִּפּוּר or יום הכיפורים), Also known as Day of Atonement, is the holiest day of the year for the Jews. Its central themes are atonement and repentance. Jews traditionally observe this holy day with a 25-hour period of fasting and intensive prayer, often spending most of the day in synagogue services. Yom Kippur completes the annual period known in Judaism as the High Holy Days (or sometimes "the Days of Awe").
Yom Kippur begins at sundown on Sun, 27 September 2020.