What's the ideal number of hours a person should work each week?

Back in the machine age, when a great many workers spent their days on assembly lines, unions fought for a 40-hour week--and researchers backed them up. After that many hours, their studies told them, productivity fell off a cliff.

But as we all know, here in America barely anyone works in a factory anymore. Therefore, new experts have proposed different numbers for the ideal workweek. One recent study shows we slack off, on average, around an hour a day at work, so maybe six or seven hours is the ideal? Others insist that, if you're doing truly creative work, four hours a day is about what you should aim for.

With so many various recommendations out there, it's entirely natural if you're a bit confused. But perhaps there's a simpler answer than all these competing numbers suggest. Maybe the best solution is to throw the idea of a set workweek out the window entirely and aim for something very different instead.

Time to kill the set workweek?

That's the contention of a thought-provoking recent post on the blog of startup Crew. In it, founder Mikael Cho explains how his team sets their own hours based on their energy levels and tries mightily to ignore the clock entirely. Their unique approach to scheduling, he writes, is based on biology.

Science, Cho correctly notes, has discovered that we each have our own unique cycle of wakeful and drowsy periods. And trying to go against your natural rhythm is a recipe for inefficiency. Natural night owls won't get more done by trying to force themselves to work like larks, and vice versa. A better bet, he contends, is to forget set schedules of any kind and follow your energy levels instead.

Keeping organized while ignoring the clock

But that sounds like chaos, you might object. Even if you agree with the underlying principle that it's counterproductive to go against your body's natural rhythms, you still need to build some sort of routine to stay organized and accountable, right?

Cho hears you. He's actually not recommending we trash structure entirely and just allow ourselves to be blown about by the whims of our energy levels. Instead, he recommends you swear off strict clock watching and instead replace it with these four scheduling principles:

  1. Write a realistic to-do list. "Make a to-do list for the day that has 3-4 major tasks that you want to get done...plan for 4-5 hours of real work per day," he writes.
  2. Create cycles with your work. Your work cycle should match your energy cycle, e.g., start with a challenging creative task, take a real break (like a nap or a walk, not fiddling with your gadgets at your desk), then a routine task, another break, another routine task, etc., until you've accomplished your reasonable to-do list.
  3. Give yourself one day with no work. "Try removing work completely for a day," suggests Cho (and most major religious traditions). "When you return to work the next day, you'll probably feel inspired and driven."
  4. Find a true metric to measure your tasks. "It's easy to count hours but not so easy to figure out another way to measure the work you do that encompasses the true goal of what you're producing," notes Cho. "For example, it's easy to measure how many hours you wrote today but what is the goal of your writing? Is it to simply get your thoughts down? Then maybe you should be measuring how many days in a row you are writing. Is it to grow your audience so people purchase what you're selling? Then maybe you should track the sales that result from each blog post you write rather than the number of posts you write."

What do you think of Cho's idea for replacing clock-watching with scheduling sanity?