The Rambam writes in Hilchos Talmud Torah:
כָּל אִישׁ מִיִּשְׂרָאֵל חַיָּב בְּתַלְמוּד תּוֹרָה בֵּין עָנִי בֵּין עָשִׁיר בֵּין שָׁלֵם בְּגוּפוֹ בֵּין בַּעַל יִסּוּרִין בֵּין בָּחוּר בֵּין שֶׁהָיָה זָקֵן גָּדוֹל שֶׁתָּשַׁשׁ כֹּחוֹ אֲפִלּוּ הָיָה עָנִי הַמִּתְפַּרְנֵס מִן הַצְּדָקָה וּמְחַזֵּר עַל הַפְּתָחִים וַאֲפִלּוּ בַּעַל אִשָּׁה וּבָנִים חַיָּב לִקְבֹּעַ לוֹ זְמַן לְתַלְמוּד תּוֹרָה בַּיּוֹם וּבַלַּיְלָה שֶׁנֶּאֱמַר (יהושע א ח) "וְהָגִיתָ בּוֹ יוֹמָם וָלַיְלָה":
Every Jewish man is obligated to study Torah, whether he is poor or rich, whether his body is healthy and whole or afflicted by difficulties, whether he is young or an old man whose strength has diminished. Even if he is a poor man who derives his livelihood from charity and begs from door to door, even if he is a husband and [a father of] children, he must establish a fixed time for Torah study during the day and at night, as [Joshua 1:8] commands: "You shall think about it day and night."
There is a mitzvah to learn “by day” and by night”. My question: are there time parameters to this this?
Meaning, does the learning at “night” need to be after certain time, like Skiyah or Tzeis? Similarly, does the mitzvah to learn by day need to be before a certain time?
