"Jewish holiday" Jeopardy™ question: it’s the first fast day after Rosh Hashanah on the Hebrew calendar.
No, not "Yom Kippur."
Not even if you phrase it in the form of a question.
The correct response is, "What is the Fast of Gedaliah?"
Tzom Gedaliah is observed on the third of the Jewish month of Tishrei — or the fourth, when 3 Tishrei falls out on a Saturday, as it did this year, 5772.
Following the Babylonian destruction of Temple in 586 B.C.E., Gedaliah was the last Jewish governor in Judea, until he was assassinated by another Jew who returned from exile to kill him.
Fifteen years ago, on the eve of the High Holidays, Rabbi Bernard Raskas — the longtime spiritual leader in St. Paul, Minn. who passed away last year — wrote a High Holiday feature for JTA that used the murder of Gedaliah to expound upon one of the most significant events of 5766:
The assassination of Prime Minister Yitzhak Rabin was far from the first political assassination in Jewish history. In biblical times, two Davidic monarchs of the Kingdom of Judah, as well as two chiefs of staff, were assassinated by fellow Jews.
While eulogizing her father, Raskas’s daughter offered the following anecdote, which readers may find inspirational in the new year:
Rabbi Bernard Raskas once told a Star Tribune reporter chronicling his impressive career that his job was to get into heaven.
"If one gets one’s name in the headlines, that’s nice, and everybody knows," he said. "But what gets one into heaven is what one does and nobody knows."
Archive Notes: Lithuanian Jews reportedly had a custom to visit the Ligmjany cemetery on Tzom Gedaliah and Tisha B’Av, but were prevented by Lithuanian authorities in 1928 … In 1937, Jewish garment workers dedicated their erev Rosh Hashanah wages to beleagured co-religionists in Europe and a group of North American Rabbis urged North American Jewry to observe Tzom Gedaliah "as a fast day in protest against persecution of Jews in Eastern Europe, particularly in Poland."
Jewish Literacy Revised Ed: The Most Important Things to Know About the Jewish Religion, Its People, and Its History by Rabbi Joseph Telushkin (pp. 670-671)