Some days are dog's day

What is the meaning of the phrase 'It's A Dog's Life?'
From what i found in the World Wide Word website by Michael Quinion, this is some of the extract;

"It certainly seems that the phrase has become more ambiguous than it once was, though I’ve not come across many examples myself of its use as a description of a pampered existence. Most of our expressions that include dog are old enough to be based in times when dogs were not cosseted, but were kept as watchdogs or hunting animals, not as pets. They often weren’t allowed in the house, but were kept in kennels, fed scraps, worked hard, and often died young. So going to the dogs, dog tired, to die like a dog, dog’s dinner, dogsbody, dog eat dog, and a dog’s life all refer to a state of affairs best avoided. Specifically, a dog’s life is first recorded in the sixteenth century and seems to have remained in the language with the sense of “a life of misery, or of miserable subserviency” ever since."

I do not really describe my life as a miserable. But I do admit that there were some days, it feels like a dog's day. Yesterday (16/May actually) is almost a dog's day. It's not so bad as those people in Myanmar and Sichuan, China at the moment, at least my dog day could have been avoided. I will post about it in day in a day or two. Got to go..