NEW YORK — At small businesses this summer, many owners won't be trying to figure out whether employees will be counting it as vacation time, personal days or sick leave when they send texts or emails that say, "I'm not coming in today."A growing number of companies combine vacation and sick time into one bucket called paid time off, or PTO. Staffers decide whether they're going to use the days for vacation, when they or a relative is ill, or for family events."You're saying to staffers, it's PTO, just take it. If you have a sick kid, need a personal day, you're really stressed out," says Gretchen Van Vlymen, a vice president at StratEx, an HR consulting firm based in Chicago.Forty-three percent of companies offered PTO in 2016, up from 28 percent in 2002, according to a report from World at Work, an association of human resources professionals. The report said 51 percent of private companies, which would include small and mid-size businesses, offered PTO last year.