While answering this question I wondered: for countries/areas that have rules such as the 90/180 rules of the Schengen Area, do airlines bother to count how long you have already been in the area?
As we all know, airlines have a duty to check documentation of boarding passengers to make sure they have the required paperwork (valid passport, valid visa or travel authorisation/electronic visa if required...). If they let someone without the relevant paperwork board and reach the destination country, they not only have to carry them back, but in many cases also face penalties (which can be quite hefty).
Airlines obviously can't check everything (they don't have all the information), but do they have to count the days a passenger has stayed in the Schengen Area in the last 180 days (by checking the stamps in the passport)? That would seem like a quite time-consuming (and error-prone) process. Or is that checked as part of Advance Passenger Information screening?
Does anyone have any experience of this? Do airlines have to do it? Do they actually do it (never / sometimes / often / always)? Do they even have enough information to do it?