Open RebBlumstein opened 5 years ago
See also the Gemara in Brachos 3a (https://www.sefaria.org/Berakhot.3a.8?ven=William_Davidson_Edition_-_English&lang=bi&with=Rashi&lang2=en) which seems to state clearly that the first watch begins with the beginning of night (Tzeis HaKochavim), and the last watch ends with the beginning of day (Alos HaShachar).
And see the Rashba there (https://www.sefaria.org/Berakhot.3a.8?ven=William_Davidson_Edition_-_English&lang=bi&with=Rashba&lang2=en) who says explicitly that the middle of the Second Watch is the same as Chatzos.
Shavua Tov! Currently, I see Midnight Guard and Morning Guard are calculated such that the watches begin and end from Sunset to Sunrise. Some hold that they are calculated as hours of the night, i.e. that the first Watch begins at Nightfall, and the last Watch ends at Alos HaShachar — the halachic night being divided into watches. This also means that Chatzos is the middle of the night — between Tzeis HaKochavim and Alos HaShachar.
Source: https://www.sefaria.org/Shulchan_Arukh%2C_Orach_Chayim.1.2?lang=he&p2=Eshel_Avraham_on_Shulchan_Arukh%2C_Orach_Chayim.1.1&lang2=he