The Book of Common Prayer would have provided the official liturgical calendar for Jamestown, Virginia, from 1607 so it may be assumed that the Dog Days likely have been known in the New World at least since that time.
Other references
For the ancient Egyptians, Sirius appeared just before the season of the Nile's flooding, so they used the star as a "watchdog" for that event. Since its rising also coincided with a time of extreme heat, the connection with hot, sultry weather was made for all time: "Dog Days bright and clear / indicate a happy year. / But when accompanied by rain, / for better times our hopes are vain."
In John Webster's 1623 play The Duchess of Malfi, the malcontent Bosola states "blackbirds fatten best in hard weather: why not I in these dog days?"
The phrase is mentioned in the short story "The Bar Sinister" by Richard Harding Davis. The main character, who is a street dog, explains "but when the hot days come, I think they might remember that those are the dog days, and leave a little water outside in a trough, like they do for the horses."
The Prologue of Tuck Everlasting, set in the first week of August, says: "These are strange and breathless days, the dog days, when people are led to do things they are sure to be sorry for after."
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