Each installation is deciding on its own how to best schedule furlough time, aiming to not adversely impact operations.
The Tooele Army Depot, for example, will switch from a 4-day, 10-hour workweek to a 5-day, 8-hour week and furlough its 500 civilian employees on Fridays, spokeswoman Kathy Anderson said.
The Dugway Proving Ground, west of Tooele, will furlough 533 civilians, and 800 will be furloughed by the Utah National Guard.
Up to 11,500 civilians will be furloughed from Hill Air Force Base near Ogden, although that number is not yet set in stone, base officials said.
"The exact implementation of the furloughs and who will be affected is still being decided," Col. Kathryn Kolbe, 75th Air Base Wing Commander for Hill said. "We will continue to keep our people updated in the days, weeks and months ahead."
The Pentagon estimates that it will need to cut $37 billion in the fiscal year that ends Sept. 30, down from $41 billion previously projected in sequestration cuts, after the White House Office of Management and Budget completed recalculations based on a spending bill passed by Congress and signed by President Barack Obama on March 26.
The 11 furlough days are down from as many as 22 days initially projected and 14 days estimated more recently, Hagel told Defense Department workers Tuesday at a Pentagon facility in Alexandria, Va.
About 68,500 of 750,000 civilian Pentagon employees who are eligible for furloughs will be exempted, according to a 10-page memo from Hagel.
The exemptions include 28,000 civilian workers at Navy shipyards who maintain vessels "because it would be particularly difficult to make up delays in maintenance work on nuclear vessels, and these vessels are critical to mission success," Hagel said in the memo.
Employees involved in intelligence and in handling foreign arms sales also will be exempted, Hagel said.
The automatic spending cuts, called sequestration, took effect March 1. Furloughs already have begun for other federal employees, including the White House staff.
Bloomberg News Service and Tribune reporter Jennifer Dobner contributed to this story.