Preferred Time of Shacharit and Mincha
אָמַר רַבִּי יוֹחָנָן: מִצְוָה לְהִתְפַּלֵּל עִם דִּמְדּוּמֵי חַמָּה. וְאָמַר רַבִּי זֵירָא: מַאי קְרָאָה — ״יִירָאוּךָ עִם שָׁמֶשׁ וְלִפְנֵי יָרֵחַ דּוֹר דּוֹרִים״. לָיְיטִי עֲלַהּ בְּמַעְרְבָא אַמַּאן דִּמְצַלֵּי עִם דִּמְדּוּמֵי חַמָּה. מַאי טַעְמָא — דִּלְמָא מִיטַּרְפָא לֵיהּ שַׁעְתָּא.
Rabbi Yoḥanan said: It is a mitzva to pray with the reddening of the sun. And Rabbi Zeira said: What is the verse that alludes to this? “Let them fear You with the sun and before the moon, generation after generation” (Psalms 72:5). Prayer, the manifestation of the fear of God, should be undertaken adjacent to sunrise and sunset. Nevertheless, in the West, Eretz Yisrael, they cursed one who prays with the reddening of the sun, adjacent to sunset. What is the reason? Perhaps, due to preoccupation, he will become confused about the hour and the time for prayer will pass.
עם דמדומי חמה – תפלת יוצר עם הנץ החמה ותפלת המנחה עם שקיעת החמה: ייראוך עם שמש – זו תפלת יוצר: ולפני ירח – זו מנחה: לייטי במערבא – על מי שמשהה תפלת המנחה עד דמדומי חמה שמא תטרף לו השעה ע"י אונס ועבר הזמן:
Preferred Time of Ma'ariv
תְּפִלַּת הָעֶרֶב אֵין לָהּ קֶבַע. מַאי אֵין לָהּ קֶבַע? אִילֵּימָא דְּאִי בָּעֵי מְצַלֵּי כּוּלֵּיהּ לֵילְיָא, לִיתְנֵי ״תְּפִלַּת הָעֶרֶב כׇּל הַלַּיְלָה״! אֶלָּא מַאי אֵין לָהּ קֶבַע — כְּמַאן דְּאָמַר, תְּפִלַּת עַרְבִית רְשׁוּת.
We learned in the mishna: The evening prayer may be recited throughout the night and is not fixed to a specific hour. The Gemara asks: What is the meaning of is not fixed? If you say that if one wishes, he may pray throughout the night, then let the mishna teach: The evening prayer may be recited throughout the night. Rather, what is the meaning of not fixed? It is in accordance with the opinion of the one who said: The evening prayer is optional.
Mincha Ketana vs Mincha Gedola
1. עדיפה תפילת מנחה קטנה מאשר מנחה גדולה.
2. עדיפה תפילת מנחה גדולה בציבור מאשר מנחה קטנה ביחידות.
3. עדיפה תפילת מנחה גדולה וסעודה לאחריה, מאשר להתפלל מנחה קטנה וקודם לכן סעודה. [הרב שמואל דוד]
Latest time one can start Shabbat
(כז) אַ֡ךְ בֶּעָשׂ֣וֹר לַחֹ֩דֶשׁ֩ הַשְּׁבִיעִ֨י הַזֶּ֜ה י֧וֹם הַכִּפֻּרִ֣ים ה֗וּא מִֽקְרָא־קֹ֙דֶשׁ֙ יִהְיֶ֣ה לָכֶ֔ם וְעִנִּיתֶ֖ם אֶת־נַפְשֹׁתֵיכֶ֑ם וְהִקְרַבְתֶּ֥ם אִשֶּׁ֖ה לַה'׃
(לב) שַׁבַּ֨ת שַׁבָּת֥וֹן הוּא֙ לָכֶ֔ם וְעִנִּיתֶ֖ם אֶת־נַפְשֹׁתֵיכֶ֑ם בְּתִשְׁעָ֤ה לַחֹ֙דֶשׁ֙ בָּעֶ֔רֶב מֵעֶ֣רֶב עַד־עֶ֔רֶב תִּשְׁבְּת֖וּ שַׁבַּתְּכֶֽם׃ {פ}
(From here we conclude that whenever a requirement of “rest” is mentioned, one must add from the weekday on to the sacred)
Strictly speaking, Shabbat begins at Sheki'a - sunset, and from that time on it is forbidden to perform Melachot. However, based on the language the Torah employs regarding Yom Kippur, the sages of the Talmud learned that there is actually a mitzvah to add a few minutes to the Shabbat, both before it starts and after it ends. This is called tosefet Shabbat, “adding time on to Shabbat.” According to most, this is biblically mandated [Yoma 81b].
When we add to Shabbat, we are essentially taking time from the mundane workweek and transforming it into something that is holy. This reflects the entire purpose of creation—making the mundane world into a more spiritual and holy place.
Different communities have different customs as to how much time to add on to Shabbat, ranging from about 15 to 40 minutes. The most prevalent custom is to light the Shabbat candles 18 minutes before sunset.
In Talmudic times, it was the custom to blow six shofar blasts before the onset of Shabbat. After blowing the third blast, it was time to light the Shabbat candles. Afterward, they would wait “the time it takes to roast a small fish” (which could theoretically be one’s last preparation before Shabbat) and then blow the final three blasts, indicating the onset of Shabbat and that all work was forbidden [Shabbat 35b]
So the time it takes to roast a fish is the same amount of time that candle-lighting should precede sunset. Well, how much time is that?
In a different context, the sages establish that the time to roast a small fish is the same time it takes takes to walk a mil, a halachic measurement related to the Roman mille passuum, which is one thousand paces. Well, how much time does that take? Somewhere between 18 and 24 minutes. Since the smallest number given is 18 minutes, it became the custom to light the Shabbat candles 18 minutes before sunset [Rabbi Yehuda Shurpin]