(FWIW, I agree that Monday is the second day, but mainly just because that's what I was raised to believe. Plus if Sunday is the end of the week, that means Saturday isn't a weekend anymore, which is nonsense.)
Friday and Sunday get different names, unrelated to Sabbath as far as I can tell -- paraskevi and kvira.
Lots of influence from Greek culture in Georgia for sure. For a fun fact, the Georgian for "Greece" is saberdzneti -- the land of the wise. Berdzeni itself means wise (as well as Greek), but I'm not certain if it's derived from an alternative historical name for the Greek.
[1]: https://www.etymonline.com/word/Monday
Edit: also wikipedia https://en.wikipedia.org/wiki/Monday
https://www.vikingeskibsmuseet.dk/en/professions/education/v...