Midweek in Madrid on a summer’s evening, it’s 25C and at 10pm the bars, cafes and squares are full of Madrileños, chatting and drinking. They’re still there at midnight, only now some are eating too. Not until 2am do the bars start to close as the crowd thins out. Most of these people will have to go to work in the morning, so the question is: when do they sleep?

The answer is, later. According to Eurostat, the average Spaniard’s day starts 90 minutes later than a German’s. When the Spaniard eats lunch the German has been back at work for two hours and when the German knocks off at 4.30pm, the Spaniard is heading back to work for another three hours. And finally, when the German is in bed at 10pm, the Spaniard is having supper before hitting the sack some time between midnight and 1am.

Spaniards sleep about 53 minutes less than the European average, but does this mean they are a nation of sleepwalkers?

Studies show that Spaniards sleep about 53 minutes less than the European average, but does this mean they are a nation of sleepwalkers? Not if people have a siesta, says Dr Isabel Vilaseca, an ear, nose and throat specialist at Hospital Clínic in Barcelona and a spokesperson for the Spanish Sleep Society. “In small towns, most people still eat at home and can take a siesta,” she says. “And lots take a siesta at the weekend, even if they can’t during the week. Our sleeping habits are closely connected to the climate. Without air conditioning it would be impossible to work in the afternoon.”

However, few people in cities can take a siesta and the problem, says Vilaseca, is that “we’re in transition from a culture that took siestas to one that doesn’t”.

It’s all very well, she says, to impose a 9-5 norm across the board, but we can’t expect people who work in construction or on the land to work in the heat of the afternoon.

Although there is growing pressure to scrap the long, split working day, Vilaseca says this is because of its impact on work-life balance, not because people are worried they’re not getting enough sleep.

“People haven’t seen it as a problem, but now that there’s a lot of anxiety about wellness, about what we eat and so on, sleep is also becoming an issue,” she says.

The other factor that affects Spaniards’ sleeping habits is that the country is in the wrong time zone. Geographically, Spain should be on Greenwich Mean Time, but in 1942 the fascist dictator Francisco Franco switched the nation to European Central Time in solidarity with Adolf Hitler. Perhaps bizarrely, until recently there haven’t been any moves to change it back.

José Luis Casero, the president of the National Commission for the Rationalisation of Spanish Schedules, which campaigns to end the split working day and revert to Greenwich time, says being in the wrong time zone affects people’s sleep and has a direct impact on their productivity.

“It’s crazy that we are in the same time zone as Berlin,” he says, because it means the circadian rhythms of Spaniards’ biological clocks are out of step. “If we changed time zones, the sun would rise one hour earlier and we’d wake up more naturally, meal times would be one hour earlier and we’d get an extra hour’s sleep.”

In due course the clocks may change, but for Spaniards, family and social life will always take priority. If enjoying a family dinner or a drink with friends means missing an hour’s sleep, then so be it.