Those forfeited days aren't the only sign of workers' vacation guilt.
When they do get away, Americans are often taking shorter trips, according to a study for Europ Assistance, a travel insurance network. The average vacation was just 1.4 weeks in 2017, down from 1.6 weeks a year earlier, Europ Assistance said.
Plus, fewer employees who travel say they can completely "check out" while they are out of the office – 54 percent said so in 2017, from 63 percent in 2014, according to Glassdoor. Two-thirds of those taking time off report doing at least some work while they are away.
"The U.S. has a culture of guilt about taking enough vacation, and it's American workers who miss out as a result," said Jessica Bisesto, a senior editor at the travel site TravelPirates.com.
Bisesto offers these tips to make the most of your vacation days before it's too late:
Travel over the holiday weekends. This year, both Christmas and New Year's Day are on Mondays, which is ideal for a long-weekend excursion. Leave on Friday night and return on Wednesday to make the most of the holiday.
Take short trips. Get just far enough out of town to see or do something new and different. There are many fantastic destinations across the country that could be just a few hours' drive from your home base.
Know what's happening at work. Taking advantage of the slow period at the office over Christmas means that you won't have to worry about a hefty workload accumulating in your absence and you'll feel less stress when you return to your desk.
If you just can't swing a last-minute getaway, ask human resources for details of the company paid time off policy. You may be able to roll over at least some of those unused days to 2018, or cash them out.
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