Most of the things that delineate others' good days from the bad are things over which they have little or no control. Realistically speaking, that is. One could simply quit a job or divorce a spouse over the balance of days in which the relationship with lover or employer are less than radiant, but most aren't willing to reorder their lives so easily or so often.
These things being so arbitrary and so inconsequential, I've decided to base my evaluation of each day on only the weather. Really, it's the deciding factor in most other people's days, so I might as well try it.
My advantage, I like to think, is that I lived in England and the upper mid-west as a child. When the day is cold or rainy, I'm delightfully reminded of my childhood and when it's sunny and pleasant, well, it's just sunny and pleasant. It's a win/win all around.
Thusly, I have concluded that every day is a good day.
I'm not sure how long I'll be able to persist in this world view but it's worked pretty well for most of the afternoon.