Despite lying far to the west of the standard Central European Time (CET) zone, Spain has been running on this time since 1942, when Spanish dictator Francisco Franco turned the clocks forward in solidarity with his allies, Nazi Germany.
Now a political party that could be the king-maker in Spain's new government is campaigning for the country to change its time zone back to Greenwich Mean Time (GMT), arguing it will improve productivity and prove a decisive break with the country's Francoist past.
Franco put Spain's clocks an hour forward in line with his ally, Nazi Germany. Photo: AFP
Ciudadanos, led by 36-year-old Albert Rivera, campaigned for Spain to turn back the clocks - quite literally - in the run up to December's general election.
And the same proposal was included in a deal that Rivera signed on Wednesday to support Socialist leader Pedro Sánchez in his bid to form Spain's next government.
"The biggest advantage of moving to GMT is that it would be a catalyst for change," Ciudadanos chief economic advisor, Luis Garicano, told Spanish daily El País when the party announced the proposal in November.
The party believes that a change in time zone could increase productivity, putting an end to Spain's culture of long working hours, and with it the traditional two - three hour lunch break.
The change would make sense for Spain, which geographically lies further west than London, yet runs on the same time as the Serbian capital Belgrade, 2,500km (1,550 miles) to the east (all of Spain except for the Canary Islands, which remain within GMT).
The time difference also explains one of Spain's most striking peculiarities: its late meal times. Despite the country running on CET, Spaniards eating patterns mirror GMT; people tend to eat lunch at what would be 1pm in London (but 2pm in Spain) and dinner at a reasonable 8pm in London (but a yawn-inducing 9pm in Spain).
A parliamentary paper in 2013 recommended Spain return to GMT bringing it in line with the UK and Portugal. It also suggested that prime time television, which usually starts at around 10.30pm, be brought forward so Spaniards could go to bed earlier.
Turning back the clocks one hour would, according to Nuria Chinchilla, professor at Spain's INSE business school, would help Spaniards "return to the natural order of our circadian rhythm (our 24-hour physiological cycle) that goes with the sun… and the sun in Greenwich, not Germany".
"If we don't (change time zones) we lengthen the day, eat very late and then don't sleep," she added.
Ciudadanos, led by Albert Rivera, want to turn back Spain's clocks. Photo: AFP
But some campaigners question whether a campaign proposal will result in a real change.
"All the parties are very receptive to our ideas and principles, but we want something concrete from the government, not only that they put the idea in their electoral programme," José Luis Casero, president of the Comisión nacional para la racionalización de los horario, which campaigns for a change in Spain's time zone, told El País in November.
Socialist leader Pedro Sánchez faces a vote of confidence in parliament next week, but if successful (he needs either the conservative Popular Party or left-wing Podemos to abstain in order to get a majority) he could be forming Spain's new government with support from Ciudadanos.
If so, Spain could be much closer to turning back the clocks and in doing so, turning its back both on its "night-owl" reputation and a Francoist legacy that, 40 years after the dictator's death, lives on.