Thirty Days has September, April, June, November, Tishrei, Shvat, Nissan, Sivan, Av and sometimes Cheshvan[1] and Kislev. Yet a reading of Mishnah Rosh Hashanah implies that whether a month has 29 days or 30 depends on when the witnesses saw the new moon and testified in Beis Din early enough to declare the thirtieth [...]

In the Yeshiva where I teach, one of my students came to me rather incredulously- “I heard that the Tenth of Teiveis falls on a Friday this year—but I thought that we cannot have fast days on a Friday? I don’t remember a fast ever falling on Friday!”

Click to see a pdf of the Rav’s article in Mishpacha: The Longest Year: The Secrets of the Jewish Calendar

Question #1: Zev is studying in Yeshiva in Eretz Yisroel and has decided that he wants to settle there, although his parents, who support him, live in Flatbush. How many days of Yom Tov should he observe?

Question #2: Avi and Rutie, who are native Israelis, have accepted teaching positions in chutz la’aretz for two years, but certainly intend to return to Eretz Yisroel afterwards. Must they observe both days of Yom Tov while they are in chutz la’aretz?