Chicago Public School teachers work almost double their required daily instruction hours, according to a new study released Monday, and the findings worry some teacher advocates as the district gets ready to extend the school day.

On average, public school teachers work 58 hours per week, according to the report, “Beyond the Classroom: An analysis of a Chicago Public School Teacher’s Actual Workday.”

The study— put together by the University of Illinois at Urbana-Champaign’s Labor Education Program — analyzed surveys from nearly 1,000 CPS teaches and found on a typical school day teachers work more than 10 hours.

Teachers can also rack up more than five additional hours during weekday evenings and on the weekend, according to the report.

“It’s at minimum a 58-hour work week, which is more than 800 hours a year beyond what is contractually obligated,” said Robert Bruno, professor of labor and employment relations and co-author of the study, in a press release. “Teaching in a Chicago public school is well beyond a full-time job.”

Right now, the length of the school day is five hours and 45 minutes for elementary schools and six hours and 45 minutes for high schools.  

Mayor Rahm Emanuel, who’s been campaigning for a 7 1/2-hour school day, announced Tuesday that he’d compromise with the Chicago Teachers Union and other opponents of the longer school day and cut elementary school days to seven hours. High schools will still have a 7 1/2-hour day come next school year.

Even with Emanuel’s half hour cut for elementary schools, some education activists say that’s too many hours for teachers with too little pay.

“I’m very concerned, having been a teacher and coming from a family of teachers, that this is going to create a situation where more and more teachers are going to leave Chicago over time,” said Donald Moore, executive director of Designs for Change, which aims to improve urban public schools.

“The more that teachers are belittled and demonized, the more we’re undermining the key resources that we need to hold in place in order to create good schools.”

Mary Anderson, executive director of Illinois’ Stand for Children, thinks otherwise.

She said extending the school day will provide more opportunities for teachers to prepare lesson plans and collaborate with other teachers, among more advantages.

“We definitely agree that teachers work really hard and are working long hours,” she said.

But she added that the “silent majority” of parents that Stand for Children works with want a longer school day.

Anderson said Stand for Children will continue to put pressure on Emanuel and the Board of Education to fulfill their original promise of the 7 1/2-hour day for all public schools.

The study also found teachers spend up to three hours during school days performing non-teaching activities, such as hall monitoring or cafeteria supervision.

“The findings are very consistent with our own experience that the typical teacher puts in far beyond the contractual required hours,” Moore said. “They are involved in a lot of nonteaching activities, such as providing security in the halls and doing things that, in adequately staffed schools, would be done by other people.”

Moore said regardless of how long the extended school day is next year, that’s still adding a “tremendous increase” on top of teachers' already long hours and demanding schedules.

There’s been a misconception that teachers don’t work hard enough, but the study disproves that, he said.

“We feel that teachers have been really mischaracterized as being lazy clock watchers,” he said.

Jill Whol of the Raise Your Hand Coalition, who served for two years as Local School Council chairwoman of Inter-American Magnet School in Lakeview, said she’s worried that teachers will burnout with the added hours to the school day.

She added that a teacher’s work is already more demanding than many other professions, including hers.

“I can get up from my computer any time and go to the bathroom or get a cup of coffee,” she said. “That’s something a teacher can’t do.”