FORTUNE — Spain is famous for late dinners, long siestas, and low productivity. And Spaniards, who can often be caught catnapping in their cars after lunch, are famous for being, well, tired. It’s just part of the Spanish condition.
Or is it?
A recent report commissioned by a Spanish congressional subcommittee tasked with tackling the negative effects of Spain’s screwy work schedule ties the problems to the country’s membership in the Central European time zone (CET). And it blames the Germans.
Spain’s late eating hours and the like can be traced back to WWII, the report says, not to some primordial Spanishness. During the war, England moved its time zone up one hour to be on German time to avoid confusion in waging war. After France was invaded in 1940, it joined as well. And in 1942, Spain and Portugal followed for good measure.
After the war, England and Portugal returned to Greenwich Mean Time (GMT), while France stayed put as its longitude is aligned with other countries in the CET zone. But Spain, which sits squarely below England (Greenwich and Valencia are almost in a direct vertical line), decided to stick with Germany and never bothered to reset its clocks to GMT.
Living an hour ahead of where one should be — and therefore having one’s biological and work schedules out of whack — gives Spaniards a perpetual feeling of jet lag, says Nuria Chinchilla, who heads the International Center for Work and Family at Barcelona’s IESE Business School and worked on the congressional report. Being tired and being productive don’t go together.
“We wake up too early and sleep almost an hour less than recommended by the WHO [World Health Organization],” Jos Collin, a Belgian researcher who worked with Chinchilla at IESE and dug up the WWII origin of the time zone.
A typical Spanish office worker’s day starts in the dark — in Barcelona, it’s almost dark at 7:30 a.m. this time of year — to get to work at 9 a.m. (which is 8 a.m., according to the sun and that worker’s body). Because there are five hours of work before his 2 p.m. lunch (a normal lunch time of 1 p.m., as far as his body is concerned), he takes a long mid-morning sandwich break. Add to that a two-and-a-half-hour lunch and siesta break imported from Spain’s rural past, and he doesn’t complete his workday until 8 p.m.
Because of this irrational schedule and marathon workday, the worker barely sees his children before he eats dinner at 9 p.m. or later. Then he may take an 11 p.m. jog (common in Spain) or check out primetime TV, which doesn’t start until 10 p.m. and ends after midnight, before starting it all again the next day. This explains why Spaniards sleep 53 minutes less per night than other Europeans, according to Ignacio Buqueras i Bach, president of the National Commission for the Rationalization of Schedules in Spain. And this sleepiness leads to lower productivity and more work absenteeism, stress, accidents, and school dropouts.
“It’s a diabolical work day. We don’t have personal time. When we get home, there’s no time or energy for caring for children,” says Chinchilla.
According to proponents of a time zone change, joining GMT and simultaneously “rationalizing” the work schedule will improve both productivity and family life.
“There’s a lot of dead time,” Chinchilla says of the current schedule. “In cities, more than 80% of the people do not return home for lunch because they don’t have time and there’s no one at home. So having two and a half hours for lunch has no sense. We need schedules in which people eat in an hour.”
According to Chinchilla, IESE research has found that companies with schedules that allow employees to compress their work hours have 30% less absenteeism and 20% higher productivity than those with rigid, long workdays.
To get there, Chinchilla advocates a three-part process. First, the country should not move its clocks forward to Daylight Savings Time next March, thereby dropping back to GMT. Second, it should force media companies to move up their news and primetime programs by one hour. And, finally, it should run an education campaign promoting the benefits of earlier, shorter lunches and compressed workdays.
Of course, rationality and culture don’t always go together. So far, some companies — mostly multinationals like Google (GOOG), Louis Vuitton, and pharmaceutical firms — have rationalized their schedules. But all except the oldest Spaniards are accustomed to the long day under which they’ve lived their entire lives (Chinchilla recalls her grandfather raging against late meals and stubbornly sticking to the pre-war schedule of 1 p.m. and 8 p.m.).
For now, the Spanish government is examining the report, and economic minister Luis de Guindos has said that he won’t just “stick it in a drawer.”
Whether the government will muster the political will to make the change in time for March 2014 is another question. And, as Chinchilla notes, with Spain in the midst of a financial crisis, the current government might not be around in 2015 if it doesn’t get to it this year. Still, she claims to be optimistic that people will see the light.
“There are still many rigid people. But all that is alive is flexible,” Chinchilla says. She pauses and knocks on the tabletop in front of her. “That which is rigid is dead.”