'Dog days' are not specific calendar days; they simply refer to the hottest days of the year, which, in the Northern Hemisphere, normally occur during July and August. In the Southern Hemisphere, the dog days take place in January and February, but the meaning is the same.
Origins of the expression
The term 'dog days' dates back to Roman times, when people noticed that the hottest days of the year seemed to coincide with the appearance of Sirius, the dog star. Sirius is one of the brightest stars in the sky and forms part of the Canis Major constellation. The ancient Romans believed that the dog star helped bring about the high temperatures, so long, hot, sunny days became known as dog days. The specific days on which they fall vary, but they always occur sometime in July and August.
The appeal of dog days
Dog days are typically the sultriest of summer. These are the days when the sun seems to refuse to budge from the sky, bathing everything in a warm haze. These are not days to embark on busy, energetic pursuits; they're best suited to simple, relaxing pleasures in which you can enjoy the sun and the lazy pace. This is the peak period of the year for family vacations, too.
Dog days in music
Dog days have inspired a number of musicians. Notably, the British singer Florence and the Machine recorded Dog Days Are Over in 2008, which reflects upon the passing of the dog days and the importance of making the most of every moment. The song was successful in a number of countries and was featured on the soundtrack for several television dramas, including Gossip Girl and Mercy. The track was later featured in the popular musical drama Glee, sung by Amber Riley and Jenna Ushkowitz.
Dog days in film and literature
Dog days have featured in other media, as well. Dog Days (Studies in German Literature Linguistics and Culture) is a curious novel by Walter Kempowski, Norma Davis, Alan Keel and Garold Davis. In the book, a German man spends his dog days occupied with an increasingly grisly outcome while his wife is away on her summer break. Likewise, Mark Freiburger's film Dog Days of Summer, released in 2007, tells the story of a mysterious drifter and how he changes the lives of two young boys forever amid the hazy warmth of summer. Both explore the darker sides of these otherwise sultry, sun-filled summer days.