Rosh Hashana 4:4-5

Rosh Hashana 4:4

Originally, testimony about the appearance of the moon was received all day on 30 Elul. It once occurred that the witnesses came late and the Levites had no idea what Psalm to sing at the afternoon sacrifice (because they didn't know if it was Rosh Hashana or a weekday). It was therefore instituted that witnesses would only be accepted until the time of the afternoon sacrifice; if witnesses came later, both that day and the next would be treated as Rosh Hashana. After the Temple was destroyed, Rabbi Yochanan ben Zakkai instituted that testimony about the moon could again be accepted all day on 30 Elul. Rabbi Yehoshua ben Korcha said that Rabbi Yochanan ben Zakkai also instituted that even if the head of the court was elsewhere, the witnesses only had to travel to where the court met.

Rosh Hashana 4:5

The order of the blessings recited during musaf on Rosh Hashana is: avos (forefathers);  gevuros (God's might); kedushas Hashem (God's holiness), including the malchiyo‎s (verses about God's kingship) and one does not blow shofar at this time; kedushas hayom (the sanctity of the day) and one blows; zichronos (verses about how God remembers) and one blows; shofros (verses about sounding the shofar) and one blows; avodah (service to God); hodaah (thanks to God);  birkas kohanim ‏(the priestly blessing) - this is the opinion of Rabbi Yochanan ben Nuri. Rabbi Akiva said, "If we don't blow shofar after malchiyos‎, why mention it? Rather, the correct order is: avos, gevuros and kedushas Hashem; malchiyos in kedushas hayom and we blow shofar; zichronos and we blow; ‏shofros ‎and we blow; avodah, hodaah and birkas Kohanim."