According to the American Heritage Dictionary, dog days are the "hot, sultry period between mid-July and September. ...(so called because Serius rises and sets with the Sun during this time)

Serius is also known as the "Dog Star." It is the in the Canis Major constellation and is the brightest star in the sky. It is about 8.7 light years from earth. That makes it a little over 51 trillion miles from earth. (51,108,926,000,000 miles from earth to be more exact.)

If a person hopped into a car and, without breaking the speed limit of 70 miles per hour, traveled on a straght line highway to Sirius, it would take about 83.4 million (83,390,841.302) years to get there (and without stopping at a rest area!)

That certainly gives a new meaning to "going to the dog(s)!"