You mean all the days are not the same? They all seem the same to me because I can't work and am about 80% nocturnal and so days are for sleeping.
I suppose I prefer a day when I am feeling awake, well, functional and up to going outdoors. Maybe a Thursday when I can go to Knit 'n' Natter.
The question I answered here, in case they change it (which they have done before), was, "What is your favorite (sic) day of the week?"