Two-thirds of convenience store owners take "less than a day" off per week and one-third toil for 12 hours or more a day, according to an industry ministry survey.

The results of the poll, underscoring harsh working conditions at such outlets, were reported to an expert meeting under the ministry on Nov. 5.

A separate survey revealed that only about 10 percent of customers believe that such outlets need to be open 24/7.

A total of 3,645 convenience store owners took part in the survey conducted by mail in August. Asked about their days off per week, 66 percent said they take "less than a day," 19 percent said "a day" and 7 percent said "two days or more."

This means that 85 percent of owners take one day or less off a week.

With regard to hours of work, which is mainly done while standing, 50 percent of the respondents said they work "between six hours and 12 hours," 29 percent said "12 hours or more" and 14 percent said "less than six hours."

Asked their opinions about the situation, one owner said, "I haven't taken a holiday in 27 years because working late at night is the norm."

Another wrote, "I basically can't get away from work completely."

An online survey of convenience store customers in July resulted in 10,000 valid responses. Just 9 percent said late-night operation is “necessary," while 41 percent said, "It's necessary depending on the areas the stores are in."

Thirty-five percent said, "It should be up to each store to decide," while 15 percent said no late-night operation is needed.

About 1,000 people were surveyed at convenience stores to see how often they use them, with 59 percent saying, "Almost daily," and 28 percent saying, "three or four times a week."

Naoki Tsuchiya, a professor at Musashi University specializing in employer-employee relations, noted that rising employment costs have made it necessary to reduce work hours of part-timers to reap profits by increasing those of owners and family members.