" When I talk about refactoring, I’m often asked about how it should be scheduled. Should we allocate two weeks every couple of months to refactoring? In almost all cases, I’m opposed to setting aside time for refactoring. In my view refactoring is not an activity you set aside time to do. Refactoring is something you do all the time in little bursts. You don’t decide to refactor, you refactor because you want to do something else, and refactoring helps you do that other thing. "
― Martin Fowler , Refactoring: Improving the Design of Existing Code