Working hours: Should companies pay more attention to employees' internal clocks?

Till Roenneberg and the case of the missing Tauben

Till Roenneberg, one of Germany's most prominent chronobiologists, has spent his career mapping the population's sleep-wake patterns. His central finding is that the German working day is calibrated for a minority: according to the research he cites, only around 20 percent of people are true "larks," or natural early risers. The rest are either night owls or, more commonly, what Roenneberg has dubbed "Tauben" (doves) — chronotypes sitting somewhere in the middle. Because the body's master clock sits in the hypothalamus near the optic nerve and locks itself to daylight, its timing is genetically anchored. "The chronotype is a fixed human trait that cannot simply be shifted," Roenneberg says. "The body doesn't care when we have meetings or when school starts." That stubbornness is what makes the German 9-to-17 schedule so costly for the two-thirds of workers who do not naturally peak at sunrise.

The Investmentbanker study and cognitive costs of mistimed work

A 2021 US study cited in the article showed that investment bankers who are morning types genuinely make better decisions in the morning, while evening types perform better after sundown. The implication, drawn out by chronobiology expert Camilla Kring, is that for knowledge work — anything that depends on concentration, attention, and memory — scheduling is itself a productivity lever. "Some people can handle complex thinking early in the morning," Kring says. "But many others can only do so in the afternoon or evening." When employees are forced to work while still in their biological night mode, creativity suffers and error rates climb, she argues. The article also notes that decision-making itself degrades: people grow more impulsive and less patient when working at the wrong biological hour. For an economy where cognitive output, not manual labor, drives value-added, this is not a marginal concern.

Camilla Kring and the Early Riser Bias in management

Kring, an internationally published chronobiology author, frames the problem as a cultural one baked into management. "Employees who are in the office early are often seen as more disciplined, reliable, ambitious, and leadership-oriented," she observes, "even when late risers work the same number of hours and deliver better results in the evening." The reason, she argues, is straightforward: managers themselves are disproportionately morning types and therefore reward visible early presence. Companies clinging to rigid core hours, she warns, lose significant resources and innovative capacity because their staff burn energy compensating for an unsuitable schedule. Permanent social jetlag — the gap between biological and social time — has also been linked in studies to obesity, diabetes, cardiovascular disease, and mental health problems. For a country facing both demographic decline and a productivity squeeze, that public-health overlay adds weight to the workplace-flexibility debate that has intensified since the pandemic.