Kelly day
n.— «The delegation…explained that firemen work one day and have the next day off with every 10th day designated as a “Kelly” day or day off. This schedule is followed except during the vacation period when the Kelly days are granted every 12th day.» —“Board Planning Fire Station Warning Lights” Winona Daily News (Minnesota) May 23, 1957. (source: Double-Tongued Dictionary)
Further reading
Trivia time! Where in the United States can you visit Soda City? If you answered Columbia, South Carolina, you’re right! This nickname apparently derives from an old practice of abbreviating Columbia as Cola. The locals then referred to the town as...
If you speak a second or third language, you may remember the first time you dreamed in that new tongue. But does this milestone mean you’re actually fluent? And a couple’s dispute over the word regret: Say you wish you’d been able...