I heard on a tape and saw on the net in something old called Torah Tidbits....relating this gemara about 8 days and Adam to the first "observance" of Channukah !!?!?! Who is the (first) perush that brings this?
h g sCHILD, new hempstead, usa
If you don't mean "Chanukah," but the holiday of the early Ovdei Avodah Zarah, as the Gemara mentions, it is a well known teaching that this is the source of the holiday that became adopted by present Ovdei Avodah Zarah. I don't know where it is first recorded.
If you actually mean Chanukah, see Maharal in Ner Mitzvah, who talks about the theme that Chanukah occurred exactly when the days began to get longer after Ma'aseh Bereishis. (Mechon Maharal edition, p. 38)