Supposedly, the star is Sirius, the dog star; because it rises and sets with the sun during summer in the northern hemisphere, its name is associated with "dog days" usually applicable to the hottest part of the year in places north of the equator.

The dog days are those from about the middle of July to the middle of August although the exact dates vary depending on where people live.

The thought behind astrobolism was connected to an old idea that this period of summer was under a bad influence, in which dogs ran mad, the air was unwholesome, sunstroke was common, and practical work was not done because of a lack of desire by people to do anything.