You must follow a distinct day and night cycle in Pokémon_ and Nuclear. This only happens in the wild area of the game. Cities and itineraries are usually day, unless it changes for the reasons of narrative.
When you enter a city, its lighting can be different from that other cities. For example, when you visit Turf field, it seems that it’s later in the day just before the evening. But it always shines. You want to know more because some Pokémon evolve into something specific when you report it at the time of the day.
Naval, for example, evolves in Mental if you have enough happiness and happens in the middle of the day. If, however, you level with the specific levels of happiness at night, you get a octal. You want to make sure that you set the level at the right time so that you can transform your desired Pokémon into the evolution form you want to use. The same goes for the Pokémon who prefer to show up at night.
Thus, while cities and itineraries remain related to the elements of history to change their lighting, the wild area relies on the internal clock of your switch. So, if you want to go out and evolve a particular Pokémon at night, visit the wild area and the same goes when you want to change a Pokémon during the day.
You have the option to manually enter and modify your switch’s clock to change the wild zone cycle to better meet your needs. You can stand in the middle of the wild zone and freely adjust these settings. To make sure all Pokémon that arise at a given time of the day arise, go to a place and come back to reset the appearances.