title: Cannot write date in BigQuery using Java Bigquery Client API
body: <p>I'm doing some ETL from a CSV file in GCS to BQ, everything works fine, except for dates. The field name in my table is TEST_TIME and the type is DATE, so in the TableRow I tried passing a java.util.Date, a com.google.api.client.util.DateTime, a String, a Long value with the number of seconds, but none worked.
  <br/>
  I got error messages like these:
  Could not convert non-string JSON value to DATE type. Field: TEST_TIME; Value: ...
  <br/>
  When using DateTime I got this error:
  JSON object specified for non-record field: TEST_TIME.</p>
  
  <pre><code>//tableRow.set("TEST_TIME", date);
  //tableRow.set("TEST_TIME", new DateTime(date));
  //tableRow.set("TEST_TIME", date.getTime()/1000);
  //tableRow.set("TEST_TIME", dateFormatter.format(date)); //e.g. 05/06/2016
  </code></pre>