Q: How did the expression “dog days” change from meaning the hottest time of the year to a period of sluggishness or stagnation?
A: When “dog days” first appeared in English in the 16th century, it referred to the hottest part of summer in the Northern hemisphere, a period once considered unhealthy and evil.
Because of the lethargy caused by the heat or fears of malignant influences, the term came to mean a period of stagnation and inactivity. Here’s the story.
The Oxford English Dictionary describes “dog days” as “the hottest part of the summer, associated in ancient times with the heliacal rising of the Dog Star in the Mediterranean area, and formerly considered to be the most unhealthy period of the year and a time of ill omen.”
The expression has its roots in Greek mythology, where Sirius is the name of the hunter Orion’s dog. In the Iliad (Book XXII), Homer refers to the star as κύν᾽ Ὠρίωνος (kun Orionos, Orion’s dog).
English borrowed the phrase from the post-classical Latin caniculares dies (dog days), which was borrowed in turn from the Hellenistic Greek κυνάδες ἡμέραι (kunades hemerai, dog days).
When the phrase first appeared in English the 16th century, it referred to the hottest days of summer. The earliest OED example, which we’ve expanded, is from The Dictionary of Syr Thomas Eliot Knyght (1538):
“Canicula, a lyttell dogge or bytche. Also a sterre, wherof canicular or dogge days be named Dies caniculares.”
The dictionary says the phrase soon took on the figurative sense of “an evil time; a period in which malignant influences prevail.” The earliest citation for this sense is from a letter by a Protestant clergyman (and later martyr) to a fellow inmate at Newgate Prison in London:
“Neither that any giddy head in these dog-days might take an ensample [example] by you to dissent from Christ’s true church” (from a 1555 letter by John Philpot in The Examinations and Writings of John Philpot, 1842, edited by Robert Eden).
The OED says the evil figurative usage is seen “now (in weakened sense): a period of inactivity or decline.”
It’s not uncommon for the sense of a usage to strengthen or weaken over time, as we note in a 2021 post. A linguist might refer to weakening as “semantic loss” or “semantic reduction.”
It’s unclear when the weakened sense of “dog days” first appeared in English, though this Oxford citation may be an early sighting or a perhaps an indication of things to come:
“What then shall wee now expect in these dogge-dayes of the worlds declining age?” (Achitophel; or, the Picture of a Wicked Politician, 1629, three sermons by the philosopher and Anglican clergyman Nathanael Carpenter).
The dictionary’s first clear example of the weakened sense, which we’ve expanded, is from a July 12, 1992, article in The New York Times about mid-level bosses being laid off in troubled economic times:
“One possibly beneficial byproduct of the managerial dog days may be that it will prepare younger people for the job- and career-jumping likely to be their lot.”
And here’s the OED’s most recent example: “In the dog-days of The Beatles, one of Paul’s plans for holding it all together had been for the world’s most fabled band to just go out and play” (“The Beatles: Stoned, sloppy—shelved!” Mojo, February 2002).
Oxford notes that “the dog days have been variously reckoned, as depending on either the Greater Dog Star (Sirius) or the Lesser Dog Star (Procyon), and on either the heliacal rising or the cosmical rising (which occurs at an earlier date).”
The heliacal rising of a star occurs when it first becomes visible above the eastern horizon at dawn just before sunrise. The cosmical rising occurs when it rises in the morning at the same time as the sun.
“The timing of these risings depends on latitude, and they do not occur at all in most of southern hemisphere,” the OED says, adding that “very different dates have been assigned for the dog days,” with their beginning “ranging from 3 July to 15 August, and their duration varying from 30 to 61 days.”
In the Calendar of the 1552 Book of Common Prayer, the dog days run from July 7 to Sept. 5. In current calendars, Oxford says, “they are often said to begin on 3 July and end on 11 August (i.e. the 40 days preceding the cosmical rising of Sirius at the latitude of Greenwich).”
The dictionary says the usage “arose from the pernicious qualities of the season being attributed to the ‘influence’ of the Dog Star; but it has long been popularly associated with the belief that at this season dogs are most liable to go mad.”