My inlaws had recently a problem with their visa.. they overstayed the "maximum number of days allowed" by two days; they were helping us to look after the baby while we were trying to arrange a full-time nanny. The overstay was due to our miscalculating the number of days.

The police at the passport control was mad at them, interrogated them for more than an hour and at the end let them know that they will have a penalty before letting them board their plane.

They are non-EU.

I assume that particular border police officer was having a bad day; most police officers do not even check the number of days stayed in the country and they are happy to let go two old people fly out of the country.

Consequently, if you are not EU, I would strongly recommend checking with the consulate.