Day and night cycle is a natural process that appeared in SimCity 4 and SimCity (2013). Its behavior and effects are modeled to simulate real life day and night cycles. Examples include slow transitions from day to night and a presence of a sunset and a sunrise.
Although there is an option of day or night, it can also be set to transition back and forth realistically according to the in game clock. Performance of the game is not affected by this process. Many mods exist to tweak the look of night and day through uploads on fansites.
- Lights in buildings remain on for the duration of the night; they do not turn on or off to mimic Sims coming or going from homes and workplaces or going to sleep.
- This process is purely for aesthetic value, and does not affect processes in the city (i.e., farmland does not require sunlight to grow crops, crime does not increase during the night, saplings do not need light to grow, etc.)
- The shadow of buildings and vegetation stay the same regardless of what time of the day it is.
- In order to see nightlighting with custom content, a patch is required, otherwise buildings will remain dark during the night cycle.