Thousands of Dallas city employees are taking the first of three unpaid furlough days Friday as the city works to address a budget shortfall of more than $30 million.

The furloughs apply to the general fund and nonuniform employees and are intended to reduce expenses while preserving jobs and employee health benefits.

Dallas City Manager Kim Tolbert said the budget gap is driven by lower-than-expected sales tax revenue and higher-than-anticipated overtime and employee medical claims.

“Furloughs are not our preferred solution; however, they enable us to reduce expenses, protect jobs and employee health benefits and continue delivering services to our residents,” Tolbert said in a statement.

The furloughs will affect several city services on Friday.

Dallas City Hall and all Dallas Public Library branches will be closed. Code compliance and homeless outreach employees are also among those affected.

Critical services, including Dallas police, fire and 911 operations, will continue without interruption.

The furloughs also affect Dallas Park and Recreation employees, though not all workers will be off on the same days.

Recreation centers, aquatic centers and pools will remain open Friday. Employees at those facilities will take their three furlough days after the school year begins.

For other Parks and Recreation employees, including those who maintain sports fields, mow city parks and perform forestry work, Friday marks the beginning of their unpaid leave.

Harold Pearl, a nine-year Dallas Parks employee, said the unexpected time off has been frustrating.

“To clean up my words a little bit, displeased,” Pearl said.

Asked how he plans to spend the day, Pearl said he intends to “chill out, stay out the way” and “try to make some money on the side.”

The remaining furlough days are scheduled for Sept. 4 and Sept. 28.

Dallas has published a list of affected departments and facilities that will be open or closed during the furlough days.