Over the past couple of months, Europeans have noticed time slipping away from them. It’s not their imagination: all across the continent, clocks built into home appliances like ovens, microwaves, and coffee makers have been running up to six minutes slow. The unlikely cause? A dispute between Kosovo and Serbia over who pays the electricity bill.

To make sense of this, you need to know that the clocks in many household devices use the frequency of electricity to keep time. Electric power is delivered to our homes in the form of an alternating current, where the direction of the flow of electricity switches back and forth many times a second. (How this system came to be established is complex, but the advantage is that it allows electricity to be transmitted efficiently.) In Europe, this frequency is 50 Hertz, meaning a current alternating of 50 times a second. In America, it’s 60 Hz.

Since the 1930s, manufacturers have taken advantage of this feature to keep time. Every clock needs a metronome, something with a consistent rhythm that helps space out each second; alternating current provides one, saving the cost of extra components. Customers simply set the time on their oven or microwave once, and the frequency keeps it precise.

At least, that’s the theory. But because this method relies on electrical frequency, when the frequency changes, so does the time. That is what has been happening in Europe.

The news was announced this week by ENTSO-E, the agency that oversees the single, huge electricity grid that connects 25 European countries. ENTSO-E said that variations in the frequency of the alternating current caused by imbalances between supply and demand on the grid have been messing with the clocks. The imbalance itself is caused by a political argument between Serbia and Kosovo. “This is a very sensitive dispute that materializes in the energy issues,” Susanne Nies, a spokesperson for ENTSO-E, told The Verge.

Essentially, after Kosovo declared independence from Serbia in 2008, there were long negotiations over the custody of utilities like telecoms and electricity infrastructure. As part of the ongoing agreements (Serbia still does not recognize Kosovo as a sovereign state), four Serb-majority districts in the north of Kosovo stopped paying for electricity. Kosovo initially covered this by charging the rest of the country more, but last December it decided it had had enough and stopped paying. This led to an imbalance: the Kosovan districts were still using electricity, but no one was paying for it.

This caused an imbalance because electricity grids work on a system of supply and demand. As Stewart Larque of the UK’s National Grid explains, you want to keep the same amount of electricity going onto the grid from power stations as is being taken off (used) by homes and businesses. “Think of it like driving a car up a hill at a constant speed,” Larque told The Verge. “You need to carefully balance acceleration with gravity.” (The UK itself has not been affected by these variations because it runs its own, separate grid.)

“They are free-riding on the system.”

This balancing act is hugely complex and requires constant monitoring of supply and demand as well as communication between electricity suppliers across Europe. The dispute between Kosovo and Serbia, though, has put this system out of whack, as the two governments have not beeen balancing their books. “The Serbians [in Kosovo] have, according to our sources, not been paying for their electricity. So they are free-riding on the system,” says Nies.

The dispute came to a temporary resolution on Tuesday, when the Kosovan government stepped up to the plate and agreed to pay a fee of €1 million for the electricity used by the Serb-majority municipalities. “It is a temporary decision but as such saves our network functionality,” said Kosovo’s prime minister Ramush Haradinaj. In the longer term, though, a permanent agreement will need to be reached.

There have been rumors that the increase in demand from northern Kosovo was caused by cryptocurrency miners moving into the area, taking advantage of the free electricity. But according to ENTSO-E, this is not the case. “It is absolutely unrelated to cryptocurrency,” Nies told The Verge. “There’s a lot of speculation about this, and it’s absolutely unrelated.” Representatives of Serbia’s power operator, EMS, refused to answer questions on this matter.

For now, “Kosovo is in balance again,” says Nies. “They are producing enough [electricity] to supply the population. The next step is to take the system back to normal, which will take several weeks.” In other words, time will eventually return to normal for Europeans — so long as they remember to update their clocks to account for those six lost minutes.