Bernard Dickman asked:
What are the earliest references to Rav Ada's Tekufa? It does not seem to be in the Gemara anywhere. How does one know that it is the third century Amora rather than some other Rav Ada?
Bernard Dickman, Brooklyn, NY, USA
The Kollel replies:
The sefer A Glimpse of Light (Dr. J Schamroth, ch. 10) quotes two sources who say that it seems to have been used by Rebbi Yochanan, who was a member of the Sanhedrin Calendar Council during the third century.
All the best,
Yaakov Montrose