Facebook API had so many breaking changes happening all the time that they decided, as a "benefit" to developers, that they would stack them all up to occur on the first of each month. This is in the name of BS called "operation developer love". And this is only for the breaking changes that get announced. The much more common scenario that ComputerGuru mentions is where stuff gets broken, acknowledged as a bug Facebook, and then never fixed. If you read the stats they publish in their blog posts, 2-3x the number of bugs get accepted than the number that get fixed, EVERY SINGLE week.