Why West-to-East Jetlag Is More Severe: A Simple Qualitative Explanation

Empirical data shows that the jetlag when traveling west-to-east feels more severe than the jetlag when traveling east-to-west. At present, the only explanation of this empirical phenomenon is based on a complex dynamical systems model. In this paper, we provide a simple alternative explanation. This explanation also explains – on the qualitative level – the empirical data on relative severity of different jetlags. 1 When Is the Jetlag More Severe: Empirical Facts and Their Current Explanation When is the jetlag more severe: empirical data. It is known that when we travel west-to-east, a jetlag feels more severe that after a similar east-to-west travel. A more specific data is given in [1]. In this paper, as a measure of severity of a jetlag, the authors selected the number of days that a body needs to fully adjust to the new time zone. The authors compared the recovery times for traveling 3, 9, and 12 time zones eastward and westward. These times are given in the following table: time shift recovery time recovery time west-east east-west 3 hours 4+ days 3− days 9 hours 14 days 8 days 12 hours 10 days 10 days Here, 4+ means a little more than 4 days, and 3− similarly means a little less than 3 days.