It's well known the gemorah in Kedushin that one should break up their day into 3rds and learn a 3rd Mishneh, 3rd Mikreh, and a 3rd Gemorah. Rashi holds this to mean that a person should learn on a weekly basis 2 days mikreh, 2 days mishneh, 2 days gemorah. Tosfos says however that one could still ask the question that a person doesn't know how long they will live for therefore they should break up their day into 3rds.
Tosfos brings however that R"T says we are somach on the fact that it says in the Gemorah in Sanhedrin that Talmud Bavli is "balulah b'mikreh, mishneh and gemorah" therefore a person can learn that and be yotzee the inyun everyday. However I think there is a fair enough makom to ask on Tosfos. Why didn't the gemorah itself give this teretz? Knowing the statement (assumingly) of R' Yochanan in Sanhedrin the gemorah itself (in Kedushin) could have said this describing how a person should set up his limud. There are probably a few ways to answer this -- and perhaps the teretz is pashut. I'm very much interested to hear what the Talmidei Chachamim by the Kollel have to say. Looking forward to your response!
Yehoshua, Yerushalayim, Eretz Yisrael
1. It seems to me that the key to this matter is that there is a distinction between the Talmud that existed in the times of Rabbi Yehoshua ben Chananya, who is the source of the teaching that one should divide one's time into 3 parts, and the Gemara of Bavel referred to by Rabeinu Tam. I will explain, b'Ezer Hash-m.
2. First, we have to explain what Rabbi Yehoshua ben Chananya meant when he said that one should spend a third of his time learning Talmud. Since Rebbi Yeshoyua ben Chananya was a Tana and lived during the time of the Mishnah, how is it possible that he required the learning of Talmud which came after the time of the Mishnah?
3. This question may be answered based on the Gemara in Bava Metzia (33a). The Gemara cites an opinion that when the Mishnah there states that the lost property of one's Rebbi should be retrieved before one retrieves his own, it refers to a Rebbi from whom one learned most of his Chochmah. Rashi (DH she'Lamdo) explains that "Chochmah" means the reasoning behind the Mishnah and the understanding of the Mishnah so that apparently contradictory Mishanayos are reconciled with each other. Rashi writes that this area of study is called "Gemara."
4. It should be pointed out that Rashi there is explaining a Beraisa, which is from the Tana'ic period. We see from there that the concept of Gemara means the understanding of the Mishnayos, as opposed merely to memorizing them, and that this concept of Gemara existed already in the time of the Mishnah.
5. If we look at the continuation of the above Gemara, in Bava Metzia 33b, we find that the Gemara cites the Mishnah: "Be careful with learning Talmud...." Rashi explains that Talmud refers to Gemara, which is the interpretaion of the Mishnah. We now may reach the conclusion that Talmud is the same as Gemara and it refers to the proper understanding of the Mishnah.
6. Accordingly, when Rebbi Yehoshua ben Chananya states in Kidushin (30a) that a third of one's time should be spent on Talmud, this means on the area of Torah which deals with the full understanding underlying the Mishnah. If one was to learn this every day one would not learn sufficient Mikra, the written Torah, because the Talmud that Rebbi Yehoshua referred to does not contain sufficient verses.
7. In contrast, Rabeinu Tam is referring to a different kind of Talmud. This is the Babylonian Talmud that we possess. Rebbi Yochanan in Sanhedrin (24a) describes our Talmud as being a mixture of Mikra, Mishnah, and Talmud -- that is, Talmud Bavli contains a lot of explanations of the verses of the Torah and Nach (this is both in the Halachic realm when the Gemara derives many Dinim from the verses, and also in the realm of Agadata when the Gemara explains the inner meaning of verses and passages of Tanach, giving the Hashkafah of the Torah), and also contains many, many Mishnayos, including those from tractates on which there is no Talmud Bavli (this is the "Mishnah" portion), and it also explains the understanding behind the Mishnayos and often asks contradictions between different Mishnayos and reconciles them (this is the "Talmud" portion).
8. I think this interpretation is evident in the words of Rabeinu Tam here that "Gemaros Bavel" is a mixture of everything. This suggests that the Gemara of Bavel that we possess now is different from the Talmud referred to by Rebbi Yehoshua ben Chananya.
Kol Tuv,
Dovid Bloom