Kelly shift
n.— «Under what is known as the “Kelly shift,” adopted by the Fire Department in 1969, firefighters worked a 27-day rotation consisting of one 24-hour shift, followed by 48 hours off. After repeating that cycle seven times, they got six days off in row.» —“Lawsuit leads to long, complicated legal battle” by Ed Kemmick Billings Gazette (Montana) Aug. 27, 2007. (source: Double-Tongued Dictionary)
Further reading
Whippoorwills, bob whites, and chickadees. How do we decide the names of birds and what to call their calls? Plus, the last syllables of Arkansas and Kansas are pronounced differently, but they come from the same etymological root. And: What’s the...
A firefighter named Steve in Newport News, Virginia, wonders why in his line of work, and for some police, certain additional kinds of days off after long unbroken shifts are called Kelly days, Kelly shifts, or Kelly time. The term most likely comes...