I'm seeing an extra Z in the timestamp when the authored timestamp has a Z.
<div class="h-entry">
  <time class="dt-published" datetime="2018-03-01T20:45:19Z"></time>
</div>
 
        {
            "type": [
                "h-entry"
            ],
            "properties": {
                "published": [
                    "2018-03-01T20:45:19ZZ"
                ],
                "name": [
                    ""
                ]
            }
        }