Line 34 and Line 70

gistfile1.txt

var clientContext;
var oWeb;
var oList;
var obj = {};
var linkLine;

var offset = -1/60 * (new Date().getTimezoneOffset());
console.log(offset);  // This prints to the inspector console, can change to alert if you want

function runWhenLoaded() {
// Create context, get the rootweb, then get the list
        clientContext = SP.ClientContext.get_current();
        oWeb =  clientContext.get_web();
        oList = oWeb.get_lists().getByTitle("Navigation");

        clientContext.load(oList);

        // Execute the queued context commands (passes back to the global vars)
        clientContext.executeQueryAsync(runOnSuccess,function() { alert("Error"); } );
    }

// Callback function for async success
function runOnSuccess() {
        // Get all list items via CAML
        var camlQuery = SP.CamlQuery.createAllItemsQuery();
        var allItems = oList.getItems(camlQuery);
        clientContext.load(allItems, 'Include(Title, NAVControlID, NAVLink, NAVTimeZoneOffset)');

        clientContext.executeQueryAsync(function(){
                var listEnum = allItems.getEnumerator();
                while (listEnum.moveNext()) {
                    var currentItem = listEnum.get_current();

                    //obj.set(currentItem.get_item('NAVControlID'), { page: currentItem.get_item('Title'), navLink: currentItem.get_item('NAVLink'), navTimeZoneOffset: currentItem.get_item('NAVTimeZoneOffset') })
                    //obj.push({ page: currentItem.get_item('Title'), navControlID: currentItem.get_item('NAVControlID'), navLink: currentItem.get_item('NAVLink'), navTimeZoneOffset: currentItem.get_item('NAVTimeZoneOffset') });
                    obj[currentItem.get_item('NAVControlID')] = {
                      page: currentItem.get_item('Title'),
                      navLink: currentItem.get_item('NAVLink'),
                      navTimeZoneOffset: currentItem.get_item('NAVTimeZoneOffset') };
                
                }
                insertHREFs(); // call after the list items get called
        }
        ,function() { alert('List get failed'); } );
   }

function insertHREFs() {
  // get all anchor tags
  var navControlLinks = document.querySelectorAll('a[data-nav-control-id]');
  for(var i=0; i < navControlLinks.length; i++) {
    var element = navControlLinks[i];
    var dataNavControlId = element.getAttribute('data-nav-control-id');
    var value = obj.get(dataNavControlId);
    concatenateURL(element, value);
  }

}

function concatenateURL(element, value) {
  if (value.navTimeZoneOffset === true) {
   var offsetURL = value.navLink.replace("~xx~", offset);
   element.setAttribute("href", offsetURL);
  }
}