Now I wonder if I could help the immigrants in my area (I'm in Hesse/Hessen), thanks for the inspiration too.
In New Zealand we get a minimum of 10 sick working days per year but some companies offer more and allow unused sick leave to accumulate.
Many countries have this system and the usual effect is that the duration people are sick for is magically never less than 2 days. It's dumb policy.
And there's an unlimited number of sick days. As long as you have a doctor's note, you still get paid, up to some ridiculous limit at which you might have to get government support instead.
15 is the average. I use it to reassure people that it's okay to take sick days, and not one of those rights that no one dares to use.
Usually, employers ask for a doctors' note after 3 consecutive sick days, but the reason for the sickness remains hidden from the employer. The note just gives a time range, nothing more.