The scenario in which students sleep in their bedrooms from 2:00 A.M. to 9:00 A.M., rush to a 9:30 A.M. class at the university, grab a quick lunch at the cafeteria, nap on the grass at about 3:30 P.M., return to class at 4:00 P.M., collapse in bed at 6:30 P.M., study in a library study room from 8:00 P.M. to 10:00 P.M., and go to a club from 10:15 P.M. to 1:30 A.M. illustrates the sociological concept of ___________.