Countdown module that hides an element when a specified date is reached
My notes:


There is no need to create a function that calls check, you can just pass check
There is no need for function hide, you only call it once, and it only has 1 line of code, I would inline that function
Very minor, but there is no need to declare endingDate inside check, I would declare it once outside of the function
You are using a revealing pattern, I would use a simple self executing pattern. On the whole if you expose 1 function that you will run only once, use a self executing function.
Once the date is passed you will be hiding that element non-stop every second, that sounds like overkill
I abhor anonymous functions, choose a meaningful name, and you can spare a line of comment ;)


My approach with these notes would be

    (function HideElementWhenTimeComes (){
      var $el = $('#element'),
          endingDate = new Date("July 25, 2016 11:06:00"),
          intervalID;

      function check() {
        var currentDate = new Date();
            if (currentDate.getTime() &gt;= endingDate.getTime()) { 
              $el.hide();
              clearInterval(intervalID);
            }
      }

      intervalID = setInterval(check , 1000 );

    })();