You do not seem to understand the post either.
This is not about working less.
Its about understanding how many days he is committed to.
What he should do is NOT call in sick for a day he does not know whether its a work day or a day off.
Then this won't be an issue. If you are not scheduled. Don't waste a sick day on your day off..
Either you are sick or you are not.
All the rest of this talk is just a smokescreen to obscure the fact that people are trying to minimize time worked and maximize dollars paid.
So much for an honest days work for an honest days pay.