public com.google.type.DateTime.Builder getStartBuilder() {
      bitField0_ |= 0x00000001;
      onChanged();
      return getStartFieldBuilder().getBuilder();
    }
<pre>
Start date time.
</pre>

<code>.google.type.DateTime start = 1;</code>
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/DateTimeRange.java