Sometimes, people can't make up his mind before the last minute.The result is last minute changes. It can be a positive or negative, depends on the context. If you are building a software, this isn't a good thing, mostly for developers, as changes will make them rework the code, re-test, and rewrite their documentation and manuals.
I have just done a last minute changes to the syllabus i made for this semester. Why would i call it last minute? Because it's 2 minutes away from Chinese New Year 2560