Compared to the amount of paid time off afforded to workers in other countries, American employees are woefully undercompensated.

In fact, the U.S. is the only advanced economy that doesn't guarantee its workers any paid vacation time. And as a result, a quarter of the country's private-sector workers don't receive any time off at all, according to the Center for Economic and Policy Research (CEPR).

A chart recently compiled by Statista journalist Niall McCarthy, citing data from the Organisation for Economic Co-operation and Development, illustrates just how wide the discrepancy in vacation days actually is between the U.S. and the rest of the world.

A total of more than 30 days of vacation time allotted to workers in France, Germany, Spain and the United Kingdom stands in stark contrast to the 10 public holidays in the U.S., which are not guaranteed to come with pay.

And even though some companies provide paid time off for employees in the U.S., the average vacation time (15 days a year, according to CEPR) does not meet the minimum amount required by law in 19 of the world's richest countries.

As Center for Economic and Policy Research senior economist John Schmitt writes, "Relying on businesses to voluntarily provide paid leave just hasn't worked. It's a national embarrassment that 28 million Americans don't get any paid vacation or paid holidays."

If there is a silver lining for vacation days in the U.S., it's that more people are using them. American workers took an average of just over 17 days of vacation in 2017, the highest level in seven years, according to a study from campaign group Project: Time Off.

That's good news for the employees taking the time they have been afforded; corresponding studies from Project: Time Off have shown that workers who used their vacation days were more likely to be promoted than those who forfeited them.

Don't miss: If you want a raise, try taking a vacation.

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