Edvard Munch, Melancholy, 1893.

Any Joe with a Twitter account will tell you that today is Blue Monday, the most depressing day of the year. It’s a claim that rests mostly on a bunch of pseudoscience and a dubious 2005 ad campaign for a travel agency. Even so, a whole cottage industry has risen up around our apparent mid-January slump—especially in the UK, where people are always kind of miserable anyway. Tesco superstores are giving away free fruit; the BBC’s Scotland bureau has urged citizens to stay cheery by reminding themselves that the ski forecast is good and that the Spice Girls may soon reunite.

Though claims as to our collective depression have long been debunked, I wondered about the origin of the phrase “Blue Monday,” which clearly predates this latest usage. There was that great New Order song from 1983, for starters, and the subtitle to Vonnegut’s Breakfast of Champions (or Goodbye, Blue Monday) and the Gershwin opera well before that. Evidence from eighteenth-century books suggests that Blue Monday was once just an excuse for working people to get drunk, and it happened every Monday, because our ancestors have long known what any casual reader of Garfielddoes: Mondays are for the birds.

Volume III of the New American Cyclopaedia (1863) says that Blue Monday was “originally called so from a fashion, prevalent in the 16th century, of decorating the churches, on the Monday preceding Lent, with blue colors. The custom … was subsequently transferred to all Mondays, indiscriminately … and, for a portion of the working classes, the blue Monday still carries with it promises of enjoyment and relaxation from labor.” The Monthly Mirror goes further, saying that those “employed in the lower kinds of trade” considered “every Monday as a day set apart for idleness”; the term Blue Monday is thus

supposed by some to have its origin in the bruises occasioned by the fists and cudgels which were in frequent use by the drunk and disorderly … the abuse prevailed to such a degree that the day was soon distinguished by debaucheries of every kind, by tumults, and frequently by murders … no journeyman tailor can be prevailed upon to work on a Monday by any prospect of reward, but generally devotes that day to the joys of Bacchus.

An 1830 Report by the New York City Temperance Society found that, by then, the practice had waned in the city, though the phrasing suggests that it was once a popular pastime. “Does ‘Blue Monday’ prevail among workmen of your profession?” a survey asked a series of mechanics. “We do not see blue Monday as often as in former years,” answered one, and several others agreed. But some were ashamed to admit that “its evils continue to exist,” and that “there are days when men become blue—as blue as indigo bags.”

Still—why blue? The Guardianof 1873 was confused by this, too. “We have looked all about us for the origin and meaning of this phrase, so indicative, apparently, of the heavenly canopy above us, but so significant, at the same time, of a torpid liver and hazy horizon with us; but have nowhere found the term even, save in a preacher’s diary.”

People could agree, at least, that Blue Mondays were for boozing and all manner of indolence. And yet, by the end of the century, the phrase seemed to have sloughed off some of its alcoholic connotations, and here its first link to depression creeps in. An 1896 piece in Good Housekeeping blames Monday’s preternatural blueness on “the custom of having wash-day,” when blue dyes were known to run. The article notes that everyone, even kids, feels afflicted by the day’s sadness: “It pervades the schoolroom; children and teachers say they are depressed by it.”

The Blue Monday Book, from 1905, agrees, noting that “every Monday may be a Blue Monday—when the soul is so enveloped in ‘the blues,’ that life can only be viewed ‘through a glass darkly.’” It offers a series of nominally uplifting quotations to buoy the melancholy spirit, but some of these are fairly blue themselves. Who among us feels better after reading “If you are happy it is largely to your own credit. If you are miserable it is chiefly your own fault”?

Every age, in short, gets the Blue Monday it deserves, and every culture must invent some new explanation for Monday’s abiding blueness. Monday is awful because the Church said it should be awful. Monday is awful because the laborers are getting drunk and killing one another. Monday is awful because it’s time to do the laundry. Monday is awful because science says so. I have to think our forebears got it right: better, in the face of such an enduring mystery, to take the day off and have a drink somewhere. “Making stupid stuff up about the most depressing day of the year,” Ben Goldacre wrote a few years back, “doesn’t help anyone, because bullshit presented as fact is simply disempowering.”

Dan Piepenbring is the web editor of The Paris Review.