@Marcus2
Not sure I understood your question as you meant it, but maybe this helps:
Here in Amsterdam whole apartments are only allowed to be rented for 60 days a year. When that's reached it's not possible to book anymore. The listing may still be visible when doing a general search without dates, but it obviously doesn't show up anymore as available for searches with specific dates.
So even if you open up all of the remaining days of the remaining year, nobody will be able to book. The full 60 days (90 days in London) that are legally allowed have been reached.