The day-to-night transition has been the holy grail for timelapse photographers since timelapse first became a thing. What makes it difficult is rather obvious. The exposure is constantly changing as time passes. But dealing with that change in exposure over the course of an hour or two is not so straightforward.
But it’s not impossible to achieve, and there are various ways to do it, as David Bergman discusses in this video. Each of the methods has their own advantages and disadvantages, and which technique you’ll use will depend on your own judgement. But this will give you a great starting point to make your own.