We are learning about the various times for saying Kerias Shema, Davening,etc. The limits are given in Shao Zemanios, Ashmoros, Chatzos,etc. As these times varied day by day through the year, how were the Chachamim and the Hamon Am able to determine exactly when these times were, especially as there were no watches and sundials were obviously not effective at night?
thank you for your time and have a gut shabbos
moshe ehrenpreis, kew gardens, new york usa
Dear Moshe,
Sundials were not the only means of measuring time in ancient times. Although to my knowledge the Talmud or Mishnayos do not discuss these other devices, I think we can assume that the Jewish people had things like hour glasses. Chatzos Lylah is exactly twelve hours after Chatzos Yom. Perhaps they had a twelve-hour glass that would tell them when Chatzos Lylah was. The same could be done for the Ashmoros haLylah. Another possibility is that - just as you can use the the stars and constellations for navigation - you can use them for telling time. In the northern hemisphere where you have the north star to point due north, you could use a star that rose above the horizon just at nightfall and follow its arc over the north star; when it reaches the top of the arc - or when it passes the imaginary line in the sky going through the north star that separates east from west - that would be Chatzos haLylah.
Furthermore, people then were probably much more sensitive to the passage of time then we are today. We have watches to rely on so we are not as tuned into signs around us that mark time. The Gemara, though, is replete with references to certain events that were faithful markers of time like the crowing of the rooster, etc. I was told of an interesting Midrash - which to date I have not been able to find - that says that Raban Yochanan ben Zakai was put in prison by Aspasianus (Vespasian) when he came to see him in the story of the Churban Beis haMikdash, and even though he was inside he was able to tell what time it was from how many Mishnayos he had learned.
You see, by the way, that measuring Chatzos Laylah wasn't easy for anyone. The Gemara (Berachos 3b) says that Moshe himself couldn't measure it exactly, and Rashi on the Pasuk "k'Chatzos" (Shemos 11:4) says that the Egyptian astronomers might miscalculate it. David haMelech new exactly when Chatzos was but the Ruach Tzaphonis that helped him is a probably a spiritual concept that was not available to the average person.
There does, however, seem to be a difference between the Chachamim and the Hamon Am regarding the ability to tell time. Tosafos (Yoma, 37) tells us that the Hamon Am in Yerushalayim would not say Krias Shema just before Netz haChamah but rather just after the Netz when they saw the Mivreshes of Hilani haMalka sparkling from the sun's rays, because they didn't know how to measure the approaching Netz accurately.
Kol Tuv,
Yonasan Sigler
This is not a Psak Halachah