gistfile1.js

/*
 * Extends Date to return the 24-hour clock time using 15 minute intervals for the 
 * minutes portion. E.x. If it is 11:04PM, this function returns 2300.
 */
Date.prototype.getInterval = function() {
  var now       = new Date();
  var intervals = ["00", "15", "30", "45", "60"];
  for(var i = 0; i < intervals.length; i++) {
    var mins = now.getMinutes();
    if(parseInt(intervals[i], 10) <= mins && mins <= parseInt(intervals[i + 1], 10)) {
      return [now.getHours(), intervals[i]].join("");
    }
  }
  return "000";
};