It is my opinion that kids in school need "personal" days, just as most of their parents probably get through their employer. Not everyone has to agree with it, which is okay by me because they're not providing for and raising my daughter.
I was fortunate to have parents who felt the same way. My brother and I rarely missed school - but there were days when we just didn't want to go (never the same day - hahahaha) and my Mom could just 'tell' if we really needed a chill day or not. And as long as there wasn't anything critical that day (test, special lesson, etc.) she would let us stay home. As long as you don't miss over two days in a row, your parents can write the note 'excusing' your absence. BTW, both of us were straight A students and first and second in our classes, respectively. I'd say we were 'allowed' 5 'chill days' or so a year, but neither of us never got really sick either so we didn't miss days for other reasons.
I hope to be able to assess my own kids to see if they need a 'chill' day once in a while too. As long as they are excelling in school and have nothing critical going on that day, I don't see a problem with it. Adults are allowed 'personal days' (or sick days - *cough cough*
) - IMO, kids need those too once in a while.