Many U.S. workers in Denver, one of the biggest federal centers outside of Washington, will go to a four-day work week in June. The experiment, certain to spread to other areas, is aimed at curbing gasoline consumption and air pollution, a serious problem in the Mile High City.

By the end of this year government officials say some Denver operations may even switch to a three-day week. This would give employes who put in 13-plus hour days superlong "weekends" of Friday, Saturday, Sunday and Monday.

Federal officials in other cities, including Washington with its giant 450,000 civilian-military complex and air pollution problems, also are considering the Denver plan for all or part of their operations.

Denver-one of the regional subcapitals of the U.S. government-is considered an ideal place to test the four-day week on a big scale. It has a substantial (28,000) but managable federal employe population that accounts for about 5 percent of the metro area work force. Like Washington, it has a large number of one and two-passenger car commuters. Statistics cited by the Denver Federal Executive Board's clean air committee indicate that 20,000 cars are used by federal commuters each day, and that they burn 22,000 gallons of gasoline daily.

Robert Dunn, regional director for the Office of Personal Management (OPM) in Denver said several agencies will go to the four-day week next month, and that the three-day week may be tested in some computer and laboratory operations. Skeleton staffs will maintain government activities in agencies that shifts to the four-day week, and agencies are expected to give some workers Monday through Thursday schedules, while others will be on duty from Tuesday through Friday. Employes and unions have been polled, Dunn said, and those in some agencies already have agreed to the 10-hour day operation without overtime.

OPM deputy director Jule Sugarman has been in Denver, and cleared the plan. He said it orginated with Dunn, Alan Merson, regional administrator of the Environmental Protection Agency, and others, and OPM will back it, and study the results.

General Services Administration is one of three Denver agencies that plan to shift to the four-day week at least in part next month.

Sugarman said he expects some agencies here and in other cities may move to the four-day week. There are major federal employe populations in Boston, New York, Chicago, Philadelphia, Seattle, San Francisco, Los Angeles, Kansas City, Dallas-Ft. Worth, Atlanta and Miami. All are studying ways to eliminate traffic and pollution.

In addition to eliminating one day of commuting each week for employes involved, Sugarman said the program could result in expanded service hours. Agencies would be open 10 hours a day through the week, and could stagger hours to provide Saturday service, too.

Congress authorized the experiment with flexible hours and shorter work weeks last year. It eliminated the requirement that government pay overtime after eight hours a day in test situations. The test will run for three years.

Thousands of Washington area workers already are working under flexible hours systems. But none, except for some super-secret communications and law enforcement units, now have the 10-hour day, four-day week. The Denver program will be the first major test of the four-day week in government, and it could prompt many related operations in industry to consider the changeover.