So I'd noticed in the most recent patch that it fixed the issue where the day of the week save information wasn't being loaded; resulting in it always being Sunday upon starting the game, and the day of the week transitioning across save files.

But just as that gets fixed, another problem crops up. The day of the week doesn't change at midnight. Which isn't a problem I had prior to the patch.

I haven't been able to figure out a consistent pattern, but I'll have the day of the week changing at random hours of the day. 8:00 AM, 6:35 PM, or so on. I even started up a new game to test if it still happened, and in that case it changed somewhere around 6:00 PM. And sometimes the day of the week won't change at all until I've used the wait function, or slept.

Meanwhile the date changes at midnight, so there's no problem there. Which tells me that whatever controls the date/calendar system is separate from what handles the day of the week transitions.

It's probably not the highest priority bug, but because of the vendors reliance on day of the week transitions to restock their goods, does make things rather annoying.

I'm experiencing the exact same issue. No mods running except the both dlc. I thought to disable and remove both and start a new game to see if something in the dlc was changing it, but it's the main game itself. Even starting a new game does nothing. I guess I just didn't notice it until now.