caching and localStorage

lsCache.js

var lsCache = function() {
  var TIMEOUT_DEFAULT = 60;
   
  var self = {
    set: function(key, val, timeout) {
      var timeout = parseInt(timeout, 10) || TIMEOUT_DEFAULT;
      var now = Math.round(new Date().getTime() / 1000);
      localStorage.setItem(key, val);
      localStorage.setItem(key + '.timeout', now * timeout);
    },
    get: function(key) {
      var timeout = localStorage.getItem(key + '.timeout');
      var now = Math.round(new Date().getTime() / 1000);
      if (timeout && timeout < now) {
        localStorage.removeItem(key);
        localStorage.removeItem(key + '.timeout');
      }
      return localStorage.getItem(key);
    }
  };
   
  return self;
};
 
var testVal = lsCache().set('key', 'value', 1);
console.log('has key');
console.log(lsCache().get('key'));
 
setTimeout(function() {
  console.log('no key');
  console.log(lsCache().get('key'));
}, 1500);