Dispute over the Calendar:
From the Mishnah, Rosh HaShanah, 2:8-9:
Images of the phases of the moon were posted on the wall of Rabban Gamaliel’s upper story. He would show them to the hediot and say, “Did you see something like this or like this?” Two came and said, “We saw it in the morning in the east and in the evening in the west.” Rabbi Yohanan ben Nuri said, “They are false witnesses.” When they reached Yavneh, Rabban Gamaliel accepted them. Another pair of witnesses came and said, “We saw it when it was anticipated and the following night we did not see it.” Rabban Gamaliel accepted them. Rabbi Dosa ben Harcynus said, “They are false witnesses. How can there be testimony that a woman has given birth, and the next day her belly is between her teeth [the woman is still pregnant]?” Rabbi Yehoshua said, “I see your point.”
Rabban Gamaliel sent him [Rabbi Yehoshua] the message, “I order you to come to me with your walking staff and wallet on the day that is Yom Kippur according to your calculations.” Rabbi Akiva went and found him depressed. He said, “I have a way of learning that everything Rabban Gamaliel does is valid, as it is said, ‘These are the special times of HaShem; Holy events which you shall declare. (Lev. 23).’ Whether at their times or not in their times, I have no special times other than these.” He came to Rabbi Dosa ben Harcynus. He said to him, “If we second guess Rabban Gamaliel’s court, we must second guess every court that has stood since the days of Moses until now, as it is said, ‘Moses and Aaron, Nadav, and Abaihu, and seventy elders of Israel (Exodus 24)’ Why are the names of the elders not made explicit? It is to teach you every three individuals who constitute a court of Israel have the status of the court of Moses.” He took his walking staff and his wallet in his hand and went to Yavneh to Rabban Gamaliel on the day that Yom Kippur fell according to his calculations. Rabban Gamaliel stood and kissed him on his head and said to him, “Come in peace my rabbi and my student; my rabbi in wisdom, and my student because you have accepted my words.”
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