There is no magic to working 8 hours every day or any other number for that matter. Before the industrial revolution, most people were farmers. They got up at

There is no magic to working 8 hours every day or any other number for that matter. Before the industrial revolution, most people were farmers. They got up at sunrise and typically worked long, hard days in the fields - workdays that were not circumscribed by any arbitrary time limit but rather defined by whatever it took to deal with the exigencies of each day. The 8-hour day, as some sort of idealized goal, came about as a direct result of the industrial revolution. With people moving to cities and taking up factory work, reformers began to characterize such work situations as exploitative, particularly of children but also of adults in terms of length of hours worked in physically demanding situations. The answer for reformers lay in having governments prescribe maximum normative work periods, with anything in excess of the prescribed maximum being deemed extraordinary and warranting extraordinary compensation. Hence, in America, we eventually got the 8-hour day and the 40-hour week. (See, e.g., http://en.wikipedia.org/wiki/Eight-hour_day http://en.wikipedia.org/wiki/Eight-hour_day for an overview). I don't think "corporate America" has any particular stake in the 8-hour day. If anything, employers would undoubtedly want to have the power to shape the work schedules of employees in more flexible ways, especially by being able to freely demand longer work hours at normal compensation as a condition of continued employment. Of course, this would require repeal of the wage-and-hour laws that today proscribe any such thing. My point, though, is that it is those laws and not any scheme by employers that keeps the 8-hour structure in place as the normative work environment. Bottom line: given pure freedom of contract, people could work any schedules they want and, in fact do so (that is what it means to be in business for yourself); however, given the problems arising from pure freedom of contract, the law imposes rigid limits deemed beneficial from a societal perspective on what may be expected of employees. That, I believe (and, I don't think, any other major factor), is what requires most people to work 8-hour schedules as their normative workday, at least in the U.S. On a final note: the typical startup environment is really a throwback to the freedom of farming days because, in the earliest stages, there basically are no formal employees but rather just founders working round-the-clock like madmen for what might often be described as "below dirt wages," and, in later stages, there are large numbers of "exempt" engineers who are not subject to the overtime rules and hence who are also working insane hours - thus, not too many 8-hour days in your prototypical startup. I don't think most of the participants regard this as exploitation, probably because most of it is self-driven, i.e., most such people want to drive themselves hard in order to succeed.