title: HL7.FHIR.R4 (C#): Literal '2020-12-01T23:00:00.000Z' cannot be parsed as a date. (at Bundle.entry[0].resource[0].birthDate[0])
body: <p>I am quite new in FHIR development, trying to learn by examples (e.g. from Gino Canessa's YouTube channel).
  In an attempt to get patients with the name containing 'test' (or anything) from the <a href="http://hapi.fhir.org/baseR4/" rel="nofollow noreferrer">http://hapi.fhir.org/baseR4/</a> server I am getting the following error message:</p>
  <pre><code>Literal '2020-12-01T23:00:00.000Z' cannot be parsed as a date. (at Bundle.entry[0].resource[0].birthDate[0])
  </code></pre>
  <p>If I try to do the same thing with the other public test server (<a href="http://vonk.fire.ly" rel="nofollow noreferrer">http://vonk.fire.ly</a>) everything functions perfectly. Obviously I am oblivious of some parameter / constraint in the request.
  This is my code:</p>
  <pre><code>using Hl7.Fhir.Model;
  using Hl7.Fhir.Rest;
  // ...
  
  List&lt;Patient&gt; patients = new List&lt;Patient&gt;();
  
  Bundle patientBundle = null;
  
  List&lt;string&gt; criteria   = new List&lt;string&gt;();
  criteria.Add($&quot;name={patientName}&quot;);
  
  patientBundle = fhirClient.Search&lt;Patient&gt;(criteria.ToArray());
  
  while (patientBundle != null)
  {
      foreach (Bundle.EntryComponent entry in patientBundle.Entry)
      {
          if (entry.Resource != null)
          {
              Patient patient = (Patient)entry.Resource;
              patients.Add(patient);
          }
      }
  
      patientBundle = fhirClient.Continue(patientBundle);
  }
  </code></pre>