Dog days Dog days The dog days or are the hot, sultry days of summer. They were historically the period following the heliacal rising of the star system Sirius, which Greek and Roman astrology connected with heat, drought, sudden thunderstorms, lethargy, fever, mad dogs, and bad luck. They are now taken to be the hottest, most uncomfortable part of summer in the Northern Hemisphere. The English name is a calque of the Latin "" (."the puppy days"), itself a calque of the Greek "kynádes hēmérai" (, "dog days"). The Greeks knew the star α Canis Majoris by several names, including Sirius (,
Sirius the Egyptian god Osiris. The name's earliest recorded use dates from the 7th century BC in Hesiod's poetic work "Works and Days". In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included "Sirius" for the star α Canis Majoris A. It is now so entered in the IAU Catalog of Star Names. Sirius has over 50 other designations and names attached to it. In Geoffrey