How often is your system "good"?


In a recent article in Stereophile, the author wrote, "When my system is good, it forces me to appreciate artists and songs I'd never noticed before."
http://www.stereophile.com/content/schiit-audio-yggdrasil-da-processor-page-2#bQow2O0DxgbPdplw.99

My presumption is that the author meant that his system sounds better some days than it does others.   I think this is an accepted fact.  I believe my system does better early in the morning and late at night due to power constraints.  I have a voltage meter on one of my outlets and I feel better about the sound when the voltage isn't sagging.  

My question for readers here is how often is your system good?   And to what do you attribute the goodness of your system from one day to the next? 
mward
System sounds great when the wife is out. 

Simply put I can crank it to realistic concert levels or the sound of real instruments and that to me is where a high end system shines most - loud, dynamic and yet absolutely crystal clear effortless sound.
Just like you should never buy a car that was built on a Monday or a Friday, my system always acts like a lemon on these two days.  Rest of the week, its just fine.
Mine sounds best when I listen to the music and forget the equipment.  Sometimes it takes a beer.
Interesting comments paraneer and wlutke, for me my system sounds great on Friday evening when my wife and daughter are out and with a beer (or two). I suppose after the bustle of the week and no opportunity to listen, Friday's seem magical.
mward-

much will depend on one's location. Most of these reviewer types resides in our major U.S. cities. For those of us who do not live in those environments, our systems should be (at the least) good to excellent daily.

I listen during the hours of midnight to 0600 for best effect.
75% of the Nation is sleeping during these hours and not consuming so much energy thus allowing this kind of musical experience.