"The master clock is set to environmental timing cues, one of the most important cues being daily cycles in sunlight and darkness.
However, if the timing of the sunlight/darkness cycles suddenly change (you fly far east or west), then it takes several days for the master clock to adjust to the new time, leading to jet lag.
"The master clock is set to environmental timing cues, one of the most important cues being daily cycles in sunlight and darkness. However, if the timing of the sunlight/darkness cycles suddenly change (you fly far east or west), then it takes several days for the master clock to adjust to the new time, leading to jet lag.
