I think there is really something to this - I barteneded my way through college, and for a couple years after (in order to travel and take care of some youthful exuberance that was incompatible with a standard job). As a result, my "money shifts" were Thursday, Friday and Saturday nights, and my days off were typically Monday and Tuesday. A lot of my friends and social circle were in the service industry as well. As a result when I decided to do the career thing, it took several years to get over "Tuesday is a day off" and "Saturday is super productive" type thoughts. Similarly, I still find evenings to be more conducive to work than mornings because my schedule was bar hours - 4 or 5 pm - 3am, and relaxing after work makes no sense, I prefer a relaxing, slow start to the day.