The circadian rhythm refers to a series of biological events that occur in a cyclical fashion over a 24-hour period: changes in body temperature, metabolic processes, hormone production, etc.
In humans, the circadian rhythm is controlled by a “biological clock” situated in the hypothalamus.
For example, our circadian rhythm controls the different phases of sleep and variations in our blood pressure.
The circadian clock is truly surprising. For example, it is constantly synchronising with the changeover between day and night.
This means that any time gap is “absorbed,” with our circadian rhythm readjusting automatically to new times.