How up-to-date are the listings? Phone Books
Each of the directories I link to update at times that suit them. They are all different.
Some official directories, such as France, update almost daily. Many of the US directories are re-keyed from printed phone books, so can take years to add a listing (and even longer to delete an old listing, if they ever do).
Most of the directories are somewhere between these extremes, with an official white pages the most likely to be fresh and a multi-country yellow pages the least likely to be accurate. Sorry, I don't know specific update dates for specific directories.