A Signal Fire, as ancient as it sounds, was one of the best methods used to send out important messages through great distances in a short time period. Stacks of wood were ready on specific mountain tops with watchers who awaited a signal to light their fire, creating a chain reaction, taking the signal from one corner of a country, to the other.
In today’s technologically advanced world, we have no necessity for such a method, but it was this method that was used in the Second Temple period (and maybe even before) to notify everyone in the Land of Israel that a New Month/Moon had arrived.
(Please read this study for an explanation of what is considered a Biblical Day, Week, Month & Year)
At that time, the first sliver of the moon had to be visibly seen by two witnesses, and confirmed to be true – at which point, the signal fires were lit going forth from Jerusalem to notify the diaspora that the moon had been sighted and proclaimed in the land of Israel.
Sighting of the Moon
A contemporary of Josephus, Philo – the Jewish historian who wrote in the first century records – “At the time of the new moon, the sun begins to illuminate the moon with a light which is visible to the outward senses, and then she displays her own beauty to the beholders.” (The Works of Philo, Special Laws II, 141, p. 581, Hendrickson, 1997)
Calling of Witnesses & proclaiming through Signal fires
The following is an extract from the Book “Golden Jerusalem” written by Professor Menashe Har-El, a historical geographer and one of the elite researchers of Jerusalem. “Golden Jerusalem” is a culmination of research and teaching on the geography and history of the Land of Israel at the Hebrew University and Tel Aviv University during a period of almost fifty years. In the course of his investigative activities, Professor Har-El has been awarded many prizes in Jerusalem and in Israel, among them: Ben Zvi Prize (1969) for his book Sinai Journeys – The Route of the Exodus; David Yellin Jerusalem Prize (1972) for his books This is Jerusalem and Travels in the Judean Desert and the Dead Sea; Jabotinsky Prize (2000) for his book The Historical Geography of the Land of Israel and Israel Prize for Land of Israel Studies (2002).
Golden Jerusalem by Professor Menashe Har-El – Page 99 to 101
The Mishnah (Rosh Hashanah 2,4) states; “whence did they carry the (chain of) beacons? From the Mount of Olives (in Jerusalem) to Sartaba, and from Sartaba to Grofina, and from Grofina to Hauran, and from Hauran to Beth Biltin”. The Tosefta mentions the mountains of Machaerus and Gador. The flares from the Mount of Olives were thus directed to Samaria, to Mount Sartaba (Alexandrion, opposite the present-day Damia Bridge) over a distance of 40 km, and thence to Galilee, the Hauran and Babylon, and also westward across the Jordan to Machaerus, 45 km from the Mount of Olives, and to Gador (Salt), visible 25 km from Sartaba.
The Ceremony of Hallowing the Month
According to the Talmud, hallowing (fixing) the new month was celebrated in Jerusalem while the Second Temple was in existence; the ceremony was probably unchanged after the Destruction, when the blessing and intercalation were done by Sanhedrin at Yavneh and later transferred to Galilee.
The month was hallowed as follows: ” There was a large court in Jerusalem called the Beth Ya’azek. There all the witnesses used to assemble, and the Beth din(house of judgment) used to examine them”. At first any man could bear witness, but when heretics became more common the witnesses had to be known to the court. Once the testimony had been accepted “the head of the Beth Din says ‘sanctified’, and all the people repeat after him, ‘sanctified’, sanctified’,” (Rosh Hashanah 2,5).
The hallowing of the month and intercalations of the year were done by three elders(sages). The Nasi(Prince) of the Sanhedrin apparently had a special court, qualified by the Great Court to hallow the month. The ceremony of intercalation attracted many spectators. The negotiations between the sages would last all night, in a closed session, and sometimes aroused the suspicions of the Roman government. Because of the fear of revolt, intercalation of the year was sometimes forbidden.
After the Sanhedrin moved to Galilee, the Nasi used to send scholars to Ein Tav, between Lod and Yavneh, to hallow the month in Judea, because of its sacred nature. The Jews of the Diaspora were notified of the New Moon by beacon signals. “How did they light the beacons? They used to bring long poles of the cedar and reeds and olive-wood and flax fluff, which they tied to the poles with a string, and someone used to go up to the top of a mountain and set fire to them, and wave them to and fro and up and down until he saw the next one doing the same thing on the top of the second mountain,and so, on the top of third mountain. whence did they carry the (chain of) beacons? From the Mount of Olives (in Jerusalem) to Sartaba, and from Sartaba to Grofina, and from Grofina to Hauran, and from Hauran to Beth Biltin. The one on Beth Biltin did not budge from there but went on waving to and fro and up and down until he saw the whole of the Diaspora before him like bonfire”(Rosh Hashanah 2,3-4). What was the “bonfire”? Each of the Babylonian Jews would light a flare and go upto his roof, so that the signalers at Beth Baltin would know the signal had been received.

The map of Signal fires that were sent out from Jerusalem
The signal of the New Moon was awaited at the various mountaintops, but the Roman government suspected the signalers of transmitting rebellious or seditious messages, since the Parthians, Rome’s enemies, lived in Babylon. In the course of time the various sects, such as the samaritans began to light signal flares at the wrong times, to confuse the distant communities, and flare signalling was no longer regarded as the chief source of information. The method continued in use, however, util the second century C.E. Rabbi Yehudah haNasi ordered the practice to be stopped, apparently on Roman instructions; the New Moon was thereafter proclaimed by messenger. The mishnah says: “Originally they used to light beacons. When the cutheans(Samaritans) adopted evil courses they made a rule that messengers should go forth”(Rosh Hashanah 2,2)
Not every month was proclaimed thus, but only the months of the Jewish festivals: “On six months messengers go out: On Nisan, because of Pesach; On Av, because of the fast; On Elul, because of Rosh Hashnanah; On Tishrei, to correct for the festivals; On Kislev, because of Chanukah; On Adar, because of Purim; And when the Temple existed, they also went out on Iyar, because of the little Pesach.”(Rosh Hashanah 1,3). *[special thanks to Elizabeth Cohen for pointing out a missing part in the quotation here… as always appreciated – 25/5/2108]
The leaders of the communities in the Diaspora awaited the instructions about the New Moon eagerly, since this was indispensable for determining the times of the festivals, and depended on the Land of Israel. It was therefore ruled that the year could not be intercalated outside the country, and any intercalation done abroad, whe it could have been done in the land of Israel, was consequently invalid. This recognition of the authority of the Nasi in the land of Israel led to unity of the people with their spiritual leaders as well as national discipline. When the Jewish community in the country grew sparse and its connections with the Diaspora weakened, Hillel the Second devised the fixed calendar in 359 C.E.; it is in use to this day.
Conclusion
The New Month was proclaimed with the sighting of the New Moon, and verified further through witnesses, as it would play a major role in calculating the Appointed/Feast Days of God. After there was sufficient discussion, the message would go out from Jerusalem to the far corners of the land of Israel notifying the diaspora, that the new month had arrived. In an age where there is no need for Signal Fires, but of greater dispersion of God’s Children around the world – may we never forget to look up into the sky for the heavenly sign God has created to make known one of His great Heavenly Appointments – The New Moon – The Beginning of the New Month.