did that mean you couldn't be out at all during the first 20 days? or did they make exceptions for that?
My schools were generally pretty understanding about it, so long as your parents phoned in to explain why you wouldn't be at school, or you had a note from your parents or doctor when you got back.
College however, they're a bit more annoying.
The college computer system will flag you up for having an especially low attendance rate, and it would be sent to your personal tutor.
They're supposed to talk to you about it, and in most cases give you official warnings and put you on contracts.
But if it was at the beginning of the year and you were being sincere about being sick, or brought in a note too, then they'd just ignore it. You can't help being sick.
The system isn't perfect, but it accomodates for unforseen circumstances.