title: Ionic 2 calendar does not pick ion-datetime from html
body: <p>I am trying to creat event in native/device calendar. I have created html form which allows to enter start and end date. Now, Ionic create event only understands start and end date as date type. What do I do? How do I convert string to datetime ot so?</p>
  
  <p>See my code below: </p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;ion-content&gt;
    &lt;ion-item&gt;
      &lt;ion-label&gt;Title&lt;/ion-label&gt;
      &lt;ion-input type="text" name="title" [value]="" (input)="title= $event.target.value"&gt;&lt;/ion-input&gt;
    &lt;/ion-item&gt;
    &lt;ion-item&gt;
      &lt;ion-label&gt;Details&lt;/ion-label&gt;
      &lt;ion-input type="text" name="details" [value]="" (input)="details= $event.target.value"&gt;&lt;/ion-input&gt;
    &lt;/ion-item&gt;
  
  
    &lt;ion-item&gt;
      &lt;ion-label&gt;Start Date&lt;/ion-label&gt;
      &lt;ion-datetime displayFormat="MMM DD, YYYY HH:mm" pickerFormat="MMM DD, YYYY HH:mm" name="startDate" (input)="startDate = $event.target.value"&gt;&lt;/ion-datetime&gt;
    &lt;/ion-item&gt;
  
    &lt;ion-item&gt;
      &lt;ion-label&gt;End Date&lt;/ion-label&gt;
      &lt;ion-datetime displayFormat="MMM DD, YYYY HH:mm" pickerFormat="MMM DD, YYYY HH:mm" name="endDate" (input)="endDate = $event.target.value"&gt;&lt;/ion-datetime&gt;
    &lt;/ion-item&gt;
  
  &lt;/ion-content&gt;</code></pre>
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  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>title: string = '';
  details: string = '';
  startDate: any = '';
  endDate: any = '';
  
  constructor(public calendar: Calendar) {
  
  }
  
  createEvent() {
  
    this.calendar.createEventWithOptions(this.title, null, this.details, this.startDate, this.endDate).then(() =&gt; {
      alert("success");
    }, () =&gt; {
      alert("Fail");
    });
  }</code></pre>
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