title: CakePHP validation for dates
body: <p>In CakePHP, is there a built-in way of validating a date to be within a certain range? For example, check that a certain date is in the future?</p>
  
  <p>If the only option is to write my own custom validation function, since it'll be pretty generic and useful to all my controllers, which is the best file to put it in?</p>