learning hilchos ha'chag -- a din in talmud torah or a din on Y"T?

The gemara (Pesachim 6a) has a din that one is supposed to start to learn hilchos pesach 30 days before the chag שואלין ודורשין בהלכות הפסח קודם הפסח שלשים יום ר' שמעון בן גמליאל אומר שתי שבתות. The gemara on the last daf in Megillah gives a different time frame and says one is supposed to learn the laws of the chag on the chag itself ת"ר משה תיקן להם לישראל שיהו שואלין ודורשין בענינו של יום הלכות פסח בפסח הלכות עצרת בעצרת הלכות חג בחג. So which is it?

Ran answers, based on the girsa of the RI"F who had the text שואלין and not שואלין ודורשין, that the din of 30 days does not require you to learn hilchos ha'chag. All it means is that if two different peole pose shaylos to a Rav at the same time, one that has to do with the chag and one that does not, from 30 days before the holiday onward all questions that relate to the holiday take precedence. (see Biur Halacha in siman 429 who discusses this Ran at length. Rashi and Tos clearly do not learn this way).

The Beis Yosef answers that the din of 30 days applies only to chag haPesach, as there is a large body of complex laws that are associated with the chag. As I've written before, the laws of Pesach touch on every area. You have your orach chaim halachos of the chag, you have to know choshen mishpat to sell your chameitz properly, you have to know yoreh de'ah to get into the laws of koshering and taaroves. You maybe get off light in the even ha'ezer dept.

The simplest answer to the question I think is that it's not an either/or choice -- embrace the power of "and." You are obligated to learn the halachos 30 days beforehand and are also supposed do so on Y"T itself (see Tos Meg 4a). The only problem with this approach is that it begs the question of why one would need to study the halachos of the chag on the chag if one already covered that material beforehand.

To help resolve this problem Rav Wahrman in Orot Pesach points out that the Rambam does not formulate the gemara in Megilah's din as an obligation to specifically learn halacha. The Rambam in tefilah 13:8 writes:

ומשה תיקן להם לישראל שיהו קוראין בכל מועד ענינו. ושואלין ודורשין בענינו של יום בכל מועד ומועד.

While the gemara refers to הלכות פסח בפסח הלכות עצרת בעצרת הלכות חג בחג, the Rambam just refers to ענינו של יום, a far broader term that encompasses any time of limud.

The Rambam in hil megillah (1:13) gives us another clue to how he understood this din. Rambam tells us that when Purim falls out on Shabbos:

ושואלין ודורשין בהלכות פורים באותה שבת כדי להזכיר שהוא פורים:

The point of learning the ענינו של יום (and I am not sure why he does not use that phrase in hil megillah, which would have bolstered R' Wahrman's argument) is not to familiarize oneself with the halachos. If you don't know what to do after studying the laws for 30 days before the chag, it is a bit too late. Rather, the point is to help in the commemoration of Y"T -- להזכיר שהוא פורים. The same would seem to hold true with respect to learning on the other Yamim Tovim. It is like a pirsumei nisa din.

I would note as well that the Rambam doesn't quote the gemara's din in hil talmud torah, where you might have expected it to be, but rather it's in hilchos tefilah, in the context of telling us what kri'as haTorah should be read on each Y"T. Just like the specific kri'ah of the day reflects and helps establish the character of the day, so too, focusing one's learning on topic matter related to the chag helps establish the character of the day.

Apart from the Rambam's chiddush as to what content matter should be studied, Rav Wahrman suggests a second nafka minah to this approach. Rashi (Meg 4) comments שואלין ודורשין. מעמידין תורגמן לפני החכם לדרוש אגרת פורים ברבים: The learning done on the day of Y"T has to be a public shiur. If the point was simply to study and know halacha, it would suffice to study shulchan aruch in the privacy of one's home. However, if the point is pirsumei nisa, or pirsum ha'chag, it makes sense that it must be a public display.

It is striking to me that Rav Wahrman does not point out that the Yerushalmi seems to say the exact opposite.

שואלין בהלכות פסח בפסח הלכות עצרת בעצרת הלכות חג בחג בבית ועד שואלין קודם לשלשים יום

Pnei Moshe: שואלין בהלכות פסח בפסח. כ״א ואחד בביתו אבל בבית ועד שמתקבצין הרבה בביה״מ ללמוד שואלין קודם לשלשים יום

The Biur Halacha quotes Chok Yaakov as suggesting that this is the resolution to the Ran's question that we started weith. The din of learning 30 days before the chag means that the topic of the chsag is the curriculum in the beis medrash where the pubic gathers to learn. The din of learning hilchos ha'chag on the chag is what one does in private, in one's home.

Rav Wahrman does raise a problem with his chiddush based on the Yalkut Shimoni on VaYakehl, our parsha:

רַבּוֹתֵינוּ בַּעֲלֵי אַגָּדָה אוֹמְרִים. מִתְּחִלַּת הַתּוֹרָה וְעַד סוֹפָהּ אֵין בָּהּ פָּרָשָׁה שֶׁנֶּאֱמַר בְּרֹאשָׁהּ וַיַּקְהֵל אֶלָּא זֹאת בִּלְבַד, אָמַר הַקָּדוֹשׁ בָּרוּךְ הוּא, עֲשֵׂה לְךָ קְהִלּוֹת גְּדוֹלוֹת, וּדְרֹשׁ לִפְנֵיהֶם בָּרַבִּים הִלְכוֹת שַׁבָּת, כְּדֵי שֶׁיִּלְמְדוּ מִמְּךָ דּוֹרוֹת הַבָּאִים לְהַקְהִיל קְהִלּוֹת בְּכָל שַׁבָּת וְשַׁבָּת וְלִכְנֹס בְּבָתֵּי מִדְרָשׁוֹת לְלַמֵּד וּלְהוֹרוֹת לְיִשְׂרָאֵל דִּבְרֵי תּוֹרָה אִסּוּר וְהֶתֵּר כְּדֵי שֶׁיְּהֵא שְׁמִי הַגָּדוֹל מִתְקַלֵּס בֵּין בָּנַי, מִכָּאן אָמְרוּ, מֹשֶׁה תִּקֵּן לָהֶם לְיִשְׂרָאֵל שֶׁיִּהְיוּ דּוֹרְשִׁין בְּעִנְיָנוֹ שֶׁל יוֹם, הִלְכוֹת פֶּסַח בַּפֶּסַח, הִלְכוֹת עֲצֶרֶת בָּעֲצֶרֶת, הִלְכוֹת הֶחָג בֶּחָג

The gemara describes Moshe's gathering of Bn"Y on Shabbos to teach them halachos, לְלַמֵּד וּלְהוֹרוֹת לְיִשְׂרָאֵל דִּבְרֵי תּוֹרָה אִסּוּר וְהֶתֵּר, and extrapolates from that to the chiyuv to do the same on Y"T. Sounds like the din of studying hilchos ha'chag on the chag is to know halacha, and not a pirsumei nisa like din.

Rav Wahrman says אכתי ישׁ לדון בּזה, but he doesn't explain further. My guess is that while his question highlights the words ְלַמֵּד וּלְהוֹרוֹת לְיִשְׂרָאֵל דִּבְרֵי תּוֹרָה אִסּוּר וְהֶתֵּר, it does not do justice to the second half of that sentence: כְּדֵי שֶׁיְּהֵא שְׁמִי הַגָּדוֹל מִתְקַלֵּס בֵּין בָּנַי. That line suggests a motivation for learning that goes beyond simply knowing issur v'heter. It sounds like the purpose of the study of the halacha was to give shevach to Hashem, not the knowledge for its own sake.

A couple of years ago I suggested that this Yalkut is not a din in talmud torah, i.e. that the mitzvah of talmud torah requires greater committment on shabbos than on a weekday, but rather the Yalkut is a din in Shabbos, i.e. a Shabbos without torah is an incomplete kiyum of mitzvas Shabbos. It would be like Shabbos without kiddush, or Shabbos without cholent. The same is true of Y"T. The chiyuv to learn hilchos ha'chag 30 days before the chag is a din in talmud torah, but learning on the y"t is a kiyum in hil' Y"T. (See this post discussing R' Zolti's chiddush that talmud torah can be a kiyum in simchas Y"T).