Don't add time precision unless authored

[gRegorLove]

HTML:

<div class="h-entry">
  <time class="dt-published" value="2018-01-12">January 12</time>
</div>

Expected result:

{
  "items": [
    {
      "type": [
        "h-entry"
      ],
      "properties": {
        "published": [
          "2018-01-12"
        ],
        "name": [
          "January 12"
        ]
      }
    }
  ],
  "rels": {
  },
  "rel-urls": {
  }
}

Current result:

{
  "items": [
    {
      "type": [
        "h-entry"
      ],
      "properties": {
        "published": [
          "2018-01-12 00:00:00"
        ],
        "name": [
          "January 12"
        ]
      }
    }
  ],
  "rels": {
  },
  "rel-urls": {
  }
}

http://microformats.org/wiki/value-class-pattern#Date_and_time_parsing
http://microformats.org/wiki/value-class-pattern##If+by+parsing+the+%22value%22+element(s)