R' Yochanan makes a statement that Rebbe Akiva is the other of our Mishnah because he makes a drasha from 'B'zmaneihem' but the Chachamim maintain that one can only read the Megillah in its proper time (14th and 15th). The Gemara eventually rejects R' Yochanan with a Tiyuvta based upon the statement of R' Yehudah.
My question is, why does the Gemara go through all the trouble with the Meitvei from R' Yehudah. The Hava Aminah that the Chachamim would hold only the 14th and 15th (and not make either drasha of B'zmaneihim or Kayamim) is ridiculous since the Gemara already quoted the Chachamim in the beginning of the Gemara (also brought on Megillah 4a and 19a) that the Chachamim were leinient and allowed the residents of the Kfarim read earlier on Yom HaKnisah - it was there Takana - so how could R' Yochanan even suggest the Chachamim would never allow anyone to read outside the 14th and 15th.
Betzalel Gersten, Mitzpeh Yericho, Israel
There are two different sets of Chachamim involved in our Gemara.
The first set of Chachamim are those Sages who were lenient and permitted the villagers to read on the Yom ha'Kenisah. However, these Chachamim followed the opinion of Rebbi Akiva, who was the author of our Mishnah, and derived from verses that the Megilah does not have to be read exclusively on the 14th or 15th.
The second set of Chachamim disagree with the first set and maintain that the Megilah may be read only on the 14th or 15th. They dispute Rebbi Akiva's position. This second set of Sages do not agree with the Derashos that allow the Megilah to be read on other days.
I later found that one of the Acharonim asks a question very similar to yours: How is it possible that there is an opinion which disagrees with the Gemara up to now, and maintains that only the 14th and 15th are viable for the Megilah?
This question is asked by the Turei Even (the author of Sha'agas Aryeh) in DH Y'G Zman. He asks, how is it possible that there is an opinion (of the Chachamim) which disagrees with what Rav Shmuel bar Yitzchak said earlier, that the 13th is a public assembly and therefore requires no verses to prove that one may read the Megilah then. If so, even if the Chachamim do not learn anything from the word "Zemanehem," nevertheless is no verse required to prove that one reads on the 13th?
The Turei Even answers that what Rav Shmuel bar Yitzchak meant before when he said that the thirteenth is a public assembly is that therefore one may derive from a Kal va'Chomer from the 11th and 12th that one may read the Megilah on the 13th. If one may read on the 11th and 12th, even though logically there is less reason to do so, then certainly one may read on the 13th, since the miracle actually happened on the 13th (as Rashi DH Zman Kehilah writes). However, now that the Chachamim say that we have no way of learning the 11th and 12th from the verses, we cannot learn the 13th from a Kal va'Chomer from the 11th and 12th either.
Kol Tuv,
D. Bloom