When the above is run, it will set to true when it is tuesday, and to false every other day of the week. One thing to notice is that the names of feature detect functions are always lowercased when added to the Modernizr object. That means that will not exist, but will. Since we only look at the returned value from any feature detection function, you do not need to actually use a function. For simple detections, just passing in a statement that will return a boolean value works just fine.