Huh, according to the map 1 AM might be somewhere in mainland Europe.
I'm in the USA and the Steam store Cyberpunk entry both in the app and web page says Dec 9 as does my library which matches up with the map.
Maybe the library date is tied to your Steam DL location. Did you choose a Steam DL site east of GMT?
I'm in Europe. and my library says Dec 9, while my DL location is same as my country and my timezone on the map is same as Paris, which will be 1 AM Dec 10