The foundational debate originates in Mishnah Berakhot 4:1, where the Sages rule that Mincha may be recited until the evening while Rabbi Yehuda holds it ends at plag ha-mincha, and the Gemara in Berakhot 27a concludes that no definitive ruling was issued either way — one who follows either opinion has acted correctly, provided one is consistent.
The Tosefta grounds the Sages' position in the practice of the daily tamid offering, which was brought until evening, as Tosefta Berakhot (Lieberman) 3:1 records: Rabbi Yehuda holds plag ha-mincha, which falls at eleven hours minus a quarter.
Both Tur, Orach Chayim 233 and Shulchan Arukh, Orach Chayim 233:1 codify this consistency requirement: one who follows the Rabbanan and prays Mincha until nightfall may not treat plag ha-mincha as night for Maariv, and one who follows Rabbi Yehuda and prays Maariv from plag onward must not pray Mincha during that same window — and the Shulchan Arukh notes that current practice is to pray Mincha until nightfall.
A critical dispute among later authorities concerns precisely where the twelve halachic hours are measured from: Mishnah Berurah 233:4 records that some calculate from dawn to tzeit ha-kochavim — meaning according to the Rabbanan Mincha extends until tzeit — while others calculate only from sunrise to sunset, meaning Mincha ends at shkiah itself according to the Rabbanan.
The Kitzur Shulchan Arukh 69:2 rules that lechatchilah Mincha should be completed by plag ha-mincha, which is one and a quarter hours before nightfall, but adds that bedieved or in a pressing situation one may pray until tzeit ha-kochavim.
The Beit Yosef, Orach Chayim 233:1 and Kaf HaChaim, Orach Chayim 233:1 both note that according to the Tur and the Rosh the lechatchilah time begins from six and a half hours, and the Kaf HaChaim adds that without pressing need one should follow the Rambam and Maran and pray only from nine and a half hours onward.
The Magen Avraham 233 records that the Maharil would pray Mincha in a pressing situation close to tzeit ha-kochavim, arguing that even where it appears to be night it is halachically still day, though he notes this applies specifically to a city whose houses are tall or that sits in a valley; he further explains that the present widespread custom of praying Mincha and Maariv back-to-back rests on the Rabbanan's view, and the congregational Maariv before nightfall is permitted only because of the difficulty of reassembling the community.
Igros Moshe OC 1:24 addresses the calculation of halachic hours and, on our reading of the cited page, warns against praying Mincha after sunset, underscoring that the controversy over whether the day-span runs from dawn or from sunrise has direct bearing on whether praying after shkiah remains within the Rabbanan's permitted window.
Mishneh Halachos (Mishneh Halachos 7:32) is not fully available in text for Mekoros to read, but our reading of the cited page indicates that the author defends the Shulchan Arukh's position that Mincha may be recited until tzeit ha-kochavim, engages the widespread debate over whether doing so after shkiah is lechatchilah or only bedieved, and references authorities who permitted it in pressing circumstances or based on different calculations of the day.
Minchas Yitzchak (Minchas Yitzchak 9:20) is not available in full text for Mekoros to read, but our reading of the cited page indicates that he addresses the prohibition of praying Mincha once one has already accepted Shabbat, a constraint that cuts off Mincha independently of the general shkiah deadline.
The Arukh HaShulchan, Orach Chaim 233:4 wrestles with the Rambam's formulation that one may pray Mincha until the sun sets, and challenges the Kesef Mishneh's reading that the Rambam intended simply to give the option of following either opinion, arguing that such a reading leaves the essential ruling unstated and creates internal tension with the Rambam's own treatment of Maariv.
