I suspect this is simple ignorance on Mr. Rogov's part, Q. He appears to be a private Israeli citizen whose webpages focus on cuisine, not calendrics. I can find no other support for Jan. 8th in this connection. The Armenian Church has a divergent position on Christmas dating, but no other extant church tradition to my knowledge currently uses anything but December 25th (either Gregorian or, in some cases, Julian). I am not sure about the Coptic Egyptian and Ethiopian churches, orthodox and monophysite, or about the Nestorians etc.

Haruo