Ring around the World simulates the elapsing of time and handles several events related to it.

A constant and very important effect is that the protagonist becomes (more) thirsty, hungry and sleepy as time goes by. Another constant and noticeable effect is that the environmental lighting changes according to the hour of the day. Other events happen when a certain time is reached.
1 in-game hour corresponds to 10 real-world minutes, but some actions might cause time to elapse more quickly.
The duration of a day is 24 hours.
The game starts at 12:00.

This video shows, at an accelerated pace, the effects of time.