set-and-clear-storage.js

var i = 0;

function setNewVal(prop) {
  window.localStorage[prop + "timestamp"] = new Date();
  //console.log(localStorage.sectimestamp + ' 1');
}

function recursive() {
  for (var prop in window.localStorage) {
    //if the property name contains the string "timestamp"
    if (prop.indexOf("timestamp") != -1) {
      //get stored timestamp val
      var timestamp = new Date(window.localStorage[prop]);
      var currentTime = new Date();

      //set maxAge
      var maxAge = (1000 * 10); //s

      console.log(currentTime - timestamp > maxAge);

      if ((currentTime - timestamp) > maxAge) {
        //if the property is too old
        //increment counter
        i++
        //get the string of the real property (this prop - "timestamp")
        var propString = prop.replace("timestamp", "");
        //send it to function that sets a new value
        setNewVal(propString);
      }
    }
  }
}

//init storage
setNewVal('timeVault');

//run check continueosly
setInterval(recursive, 1000);
//localStorage.clear();