Doesn't have to be legit sick days, but days you've used. My work gives us two weeks a year for just sick pay, but I've averaged about 1-2 days a year. It stacks year after year too.
I do get peeved when I see worse workers using it all up as if it's personal time. Better workers, not so much, but they generally don't bounce.
"All I have is my balls and my word, and I don't break them for anyone!"-Tony Montana