on_x.js

var onLocked;
device.screen.on('off', function () {
  onLocked = 0;
  var now = new Date();
  onLocked = new Date(now.getFullYear(), now.getMonth(), now.getDate(), now.getHours(), now.getMinutes(), 0, 0);
});

device.screen.on("unlock", function(){

  var timeDiff = Math.floor((new Date().getTime() - onLocked.getTime())  / 1000 ); // Minutes

  if(timeDiff > 60) {
    feeds.weather.get(
      {
        location: 'Linköping',
        locationtype: 'city',
        unittype: 'm'
      },
      function onSucess (weather, textStatus, response) {
        var messageBox = device.notifications.createMessageBox('Weather info');
        messageBox.content = "It's " + weather.now.temperature + "C, Rain:" + weather.now.rain + "% It's " + weather.now.sky;
        messageBox.buttons = [ 'Ok' ];
        messageBox.show();
      }
    );
  }
});