http://www.numachi.com/~ccount/hmepa/…2.Gamelion.html
Gamelion 7 is January 28.
That was my initial take, but I firmly believe that's now wrong in light of the misinterpretation of Apollodorus' reference in Diogenes Laertius per Alpers, Lewis, and others. Epicurus was not born on Gamelion 7. He was born in the 7th month of the Attic calendar, Gamelion. Apollodorus doesn't give a day.
According to the website, Gamelion 20, 2nd year of the 700th Olympiad, will be Feb. 10/11, 2023.
That explains it. I was one day off in my calculation due to a moving day.
I'll have to go back and check my numbers and revise the chart.
(Edit: My error in calculation was in adding a +1 to the date of every 20 Gamelion entry. All of the other columns were accurate. I am currently reviewing my BCE dates to make sure they are still accurate given measuring inconsistency).