Jet lag, medically referred to as desynchronosis and rarely as circadian dysrhythmia, is a physiological condition which results from alterations to the body's circadian rhythms resulting from rapid long-distance trans-meridian (east–west or west–east) travel on high-speed aircraft. For example, someone travelling from New York to California feels as if the time were three hours later than local time. (Source)
As pilots often have to travel between multiple time-zones, especially during long haul flights, with as much as 12 hours of difference between them, how do they fight jet lag?