More businesses observe Thanksgiving and Christmas than any other U.S. holiday. But close behind are New Year's Day, Memorial Day and Labor Day, all observed by at least 94% of businesses.

According to a Society for Human Resource Management survey, the only other U.S. holidays to exceed a 50% closure level in 2015 will be Independence Day (the Fourth of July hits on a Saturday in 2015) and the day after Thanksgiving, both at 76%; and the day before Independence Day (60%), a Friday next year.

Christmas Eve doesn't quite make the cut at 47%. Other holidays grabbing significant market share:

• Martin Luther King Jr.'s birthday, Monday, Jan. 19 (37%)
• Presidents Day, Monday, Feb. 16 (35%)
• Good Friday, April 3 (28%)
• Veterans Day, Wednesday, Nov. 11 (20%)
• Columbus Day, Monday, Oct. 12 (16%)

On average, SHRM found, most U.S. businesses will observe nine paid holidays in 2015. About one in five offers 10 paid holidays to fulltime and part-time workers, and about one in 20 offers 13 or more paid holidays. About a third offer floating holidays, with 43% offering one, 29% offering two, and 28% offering three or more.

Asked about weekend schedules, 64% said they were closed, 26% were open on Saturday, and 9% on Sunday.

The data came from nearly 500 randomly selected human resources managers.