Noam Beit Midrash - Good Public Policy

(4) These are the set times of God, the sacred occasions, which you shall celebrate each at its appointed time:

(1) God said to Moses and Aaron in the land of Egypt: (2) This month shall mark for you the beginning of the months; it shall be the first of the months of the year for you.

(4) For two of the months [people reporting the new moon are allowed to] break Shabbat: for Nissan and Tishri, for on those months messengers go forth to Syria and in them the dates of the festivals are fixed. When the Temple stood they used to be allowed to break Shabbat for all the months, in order that the sacrifice might be offered on the right day.

(5) Whether [the new moon] was seen clearly or was not seen clearly, they are allowed to break Shabbat on account of it. Rabbi Yosei says: if it was been seen clearly they may not break Shabbat for it.

(6) It happened that more than forty pairs of witnesses were on their way [to Jerusalem on shabbat] and Rabbi Akiva stopped them in Lod. Rabban Gamaliel sent a message to him saying: if you prevent the public [from coming to provide testimony] it will turn out that you cause them to stumble in the future.

(5) There was a large courtyard in Jerusalem, and it was called Bet Yazek. There all the witnesses used to assemble and the court would examine them there. They would make large feasts for them there so that they would have an incentive to come.

Originally they weren't allowed to leave the place the whole day [if it was shabbat], but Rabban Gamaliel decreed that they could go two thousand cubits from it in any direction.

And these were not the only ones [who could go two thousand cubits in any direction on shabbat], but also a midwife who has come to deliver a child, or one who comes to rescue from a fire or from bandits or from a river in flood or from a building that has fallen in all these are like residents of the town, and may go two thousand cubits [on Shabbat] in any direction.