And so it is the penultimate daf of Masechet Brachot.
אמר רב ספרא, רבי אבהו הוה משתעי: כשירד חנינא בן אחי רבי יהושע לגולה היה מעבר שנים וקובע חדשים בחוצה לארץ
Rav Safra said: Rabbi Abahu would relate: When Hanina, son of Rabbi Yehoshua’s brother, went to the diaspora, [Babylonia], he would intercalate years and establish months outside of Eretz [Yisrael]. [Because Judaism in Eretz Yisrael had declined in the wake of the bar Kokheva rebellion, he considered it necessary to cultivate the Jewish community in Babylonia as the centre of the Jewish people. Among other things, he intercalated the years and established the months even though the halakha restricts those activities to Eretz Yisrael]
The Koren notes: