sdk/src/com/socialize/google/gson/DefaultDateTypeAdapter.java
public JsonElement serialize(Date src, Type typeOfSrc, JsonSerializationContext context) {
    synchronized (localFormat) {
      String dateFormatAsString = enUsFormat.format(src);
      return new JsonPrimitive(dateFormatAsString);
    }
  }
public JsonElement serialize(Date src, Type typeOfSrc, JsonSerializationContext context) {
    synchronized (localFormat) {
      String dateFormatAsString = enUsFormat.format(src);
      return new JsonPrimitive(dateFormatAsString);
    }
  }
See issue 162