Denver Public Schools, the largest school district in the state with a student enrollment of over 92,000 students, said Tuesday it is canceling classes on Friday due to huge number of teachers joining their peers in a classroom walkout and rally at the state Capitol.

DPS will join over a dozen Colorado school districts — including Aurora, which decided Monday night to also cancel classes Friday — to close their schools or release students early because of the demonstrations planned Thursday and Friday at the Capitol. The moves affect over half of the 910,000 students enrolled at Colorado schools.

About 10,000 teachers are expected to participate in the day-long demonstrations, which will also include lobbying lawmakers and “grade-ins” to show how much work teachers do outside the school day.

DPS originally was scheduled to hold classes on Friday but release students early.

But on Tuesday, DPS said “due to significant anticipated teacher absences,” it would cancel all classes Friday.

“This still is a working day for DPS staff, and teachers and others participating in the rally must work with their supervisor to take an appropriate leave. Employees must take personal leave, unpaid leave or can contact a Denver Classroom Teachers Association representative to ask if they can use a union business day,” said Will Jones, DPS spokesman.

DPS innovation schools and charter schools can opt out of canceling classes and decide to operate on a normal schedule, Jones said.

Because of the large number of teachers in Aurora Public Schools heading for the Capitol on Friday. “we will not be able to maintain productive learning environments for our students,” according to a APS statement.

A similar walkout and rally drew hundreds of teachers earlier this month and prompted the Englewood School District to shut down. Teachers say they are angry about low teacher salaries and threats to the Public Employee Retirement Fund.