"The early bird gets the worm!" a host of productivity experts remind those who struggle to jump out of bed at dawn. But hectored night owls have a powerful new ally.

"Actually, science says I should sleep in," they can now reply.

If you naturally come alive at night and feel like a zombie before midmorning no matter what you do, you've no doubt spent most of your life being nagged by well-meaning parents, teachers, and advice peddlers to mend your ways and become a morning person. But studies are piling up that show, by and large, we're stuck with the rhythms we're born with.

There's no fighting your natural rhythms...

One recent piece of research from genetic testing company 23andMe suggests that much of our preferences regarding our schedule might be down to our genes. And it's not just Silicon Valley startups that say so. "Every organism, from primitive bacteria to human beings, have a biologically determined, internal body clock," Till Roenneberg, a professor of chronobiology at the Institute of Medical Psychology at Ludwig-Maximilian University in Munich explained to the BBC recently. "And that clock can vary greatly depending on the person."

"It's like feet," the article quotes Roenneberg as saying. "Some people are born with big feet and some with small feet." Sorry, early risers, night owls can't transform into morning people any more than you can change the size of your sneakers.

... and employers shouldn't ask us to try.

The BBC piece by By Renuka Rayasam takes this science and runs with it in a direction that will please anyone who has shuffled foggy-headed through decades of early morning start times. "A growing field of research now shows that, for many of us, our work schedules are wildly out of sync with our natural body clocks--and experts are urging employers to take notice," writes Rayasam.

If that's music to your ears, the full article is worth a read. But here's the essence of the findings: according to work by Christopher Barnes, a University of Washington management professor, the mismatch between many employees' natural preferences and the workday's official start not only results in decreased productivity and creativity (not to mention increased misery), but might also impact the ethical decisions of late risers forced out of bed prematurely.

It's a common problem, according to Roenneberg. "Many people suffer from what he calls social jetlag," Rayasam reports. "In other words, their bodies are always in the wrong time zone. He estimates that more than 70 percent of people get up earlier than they should if the goal is to be well rested and perform their best."

If you have to drag yourself to work every morning, you can at least console yourself that you have plenty of company. But perhaps a more helpful takeaway from this science would be for more bosses to consider whether the workday ought to begin a little later. Paul Kelley of the University of Oxford's Sleep and Circadian Neuroscience Institute, for one, "believes that the ideal work day should start at 10 a.m."

Or better yet, maybe leaders should think about letting their employees set their own hours. Studies show teams given this flexibility work more and collaborate better. Of course such an arrangement won't work in all environments, but there are many where the only thing stopping such a potentially productivity-boosting change is tradition and inertia.

Do you really need to force your people to report at 8 or 9 a.m.?