Up to what distance from the court is a witness who saw the moon obligated to travel and testify?
Halacha 1: if the distance is a night and a day or less, the witness is obligated to travel. Beyond that, his testimony would not help since the month would already have been extended.
Question 2
In our time (after the destruction), for which months' Rosh Chodesh may Shabbat be desecrated for moon testimony?
Halacha 2: in our time, Shabbat is desecrated only for Nisan and Tishrei because of the festivals. In Temple times it was desecrated for all months due to the Musaf offering.
Question 3
What did Rabban Yochanan ben Zakkai enact after the destruction regarding moon testimony?
Halacha 6: before the destruction, testimony was limited to before Minchah to allow time for Temple offerings. After the destruction, Rabban Yochanan ben Zakkai enacted all-day acceptance, even near sunset.
Question 4
For how many months were messengers sent to announce Rosh Chodesh?
Halacha 9: messengers were sent for six months — Nisan, Av, Elul, Tishrei, Kislev, and Adar. In Temple times, also for Iyyar because of Pesach Sheni.
Question 5
According to the Rambam, when are late witnesses in Nisan or Tishrei accepted without any intimidation?
Halacha 18: if witnesses come in Nisan or Tishrei before mid-month, their testimony is accepted without intimidation since there is still benefit for establishing the festivals in time.