They work just like they did in TOS, where everything is made up and the stardates don’t matter.
For real tho. The TOS season 2 writer’s bible (which you can find online) basically says the stardate number is a complex calculation that depends not only on time, but your location in the galaxy. I would not be surprised at all if the showrunners/writers are aware of this and are purposely doing it as an homage.
Yeah, I mean, practically, it doesn’t make much sense. In the bible’s context, I think Roddenberry was just giving potential writers (like all their guest writers) an out to not have to worry about their date falling into some continuity with another episode, and just made it sound more science-y to explain it away. Really, back then, he didn’t really care so much for technical jargon, as long as the story was good and made sense for the characters (this point is also essentially stated in the bible). If you’ve never read that bible, I highly recommend it, especially if you like behind the scenes kind of stuff. It gives you a bit about what Roddenberry was thinking back then in his approach to the show. Even has a joke or two sprinkled in.