I think days are desynced with save times themselves, so whatever it is that crashes might not be related to saving directly.

If its just once, then i'd carry on. Probably some random issue with memory (some other program bloating it in the background or game itself having a leak) New day would be one of the moments when stuff gets shuffled around there.

I think in all hundreds of hours of V it crashed flat like that once for me and it was chrome throwing a fit, that glitched the GPU driver that borked the game.