No one likes it when long-established routines are upset, so it’s understandable that D.C. firefighters are pushing back — hard — against a proposal that would dramatically change their work hours. But neither habit nor convenience should trump the public good. An altered work schedule has the potential to save money while ensuring better emergency services.

Kenneth B. Ellerbe, chief of the D.C. Department of Fire and Emergency Medical Services, is advancing a plan to shorten the length of firefighter shifts from 24 to 12 hours. Instead of working one 24-hour shift and then getting three days off, firefighters would work three 12-hour day shifts, then three 12-hour night shifts and then have three full days off. Mr. Ellerbe said the change would help curb excessive overtime while enabling (through attrition) a reduction in the number of full-time employees, eventually saving $36 million per year.

Whether the so-called 3-3-3 plan is the best combination is to be determined, but the chief is persuasive on the need to reexamine the 24-hour shift. Shorter shifts would allow for more training opportunities. And as the bulk of department duties shifts from fighting fires to providing emergency medical care, the risk of mistakes caused by exhaustion increases. There’s a reason the medical profession is moving away from working interns 24 hours a day. The EMS division of the department is already on 12-hour shifts, and if the department is truly to be unified, as recommended by the task force that examined the shoddy medical treatment surrounding the 2006 death of journalist David E. Rosenbaum, its schedules should be aligned.

Mr. Ellerbe could seek legislative approval for the change, which is supported by Mayor Vincent C. Gray (D), but he wisely hopes to reach an agreement at the bargaining table. Since firefighters, paid annually, would work more hours per week under the new scenario, more compensation is in order, particularly since they have not had a raise since 2006.

More money won’t appease everyone who has built a life around a work schedule that — with its requirement of just eight or nine workdays a month — allows extended time with families, second jobs and the ability to live as far away as North Carolina. Ed Smith, president of the firefighters union, says he believes the change will prompt an exodus from the department, including by EMS-qualified firefighters who were recruited to upgrade the department in the wake of the Rosenbaum case.

Mr. Ellerbe needs to pay attention to concerns raised by the union and allow for give and take. Ultimately, though, the issue must be decided by the question of who benefits. Arguments about firefighting tradition, what other cities do or the imposition on private lives can’t carry the day.