https://www.pcgamer.com/metro-exodus-day-night-cycle-changes-npc-behavior-dynamic-weather-can-mask-footsteps/

We got a bit of hands-on time with Metro Exodus during E3 week. The survival FPS from 4A Games is bigger than both the earlier Metro games put together, and is structured differently, too: while there are linear portions of Exodus, there are also large open world areas where players can freely explore. There's also dynamic weather and a day-night cycle.

Players can manipulate this day-night cycle: resting lets players fast-forward the clock, and that could prove useful at times because NPC behavior might change at different times of day.