Gson does not support deserialization of Microsoft's DateTime format out of the box. This custom JsonDeserializer is registered for the Date type. Gson will use it to deserialize for the Date type instead of its default. The same can be done for any other type, if you want to serialize/deserialize it in a custom way. More info: https://stackover…

JsonDeserializer -- .net DateTime to Java Date

// more info: https://stackoverflow.com/a/12878774
Gson gson = new GsonBuilder().registerTypeAdapter(Date.class, new JsonDeserializer<Date> () {
  public Date deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException {

    // example string: "/Date(1513943979489+0000)/"
    String s = json.getAsJsonPrimitive().getAsString();

    // A plus sign (+) indicates hours ahead of GMT and a minus sign (-) indicates hours behind GMT
    // https://docs.microsoft.com/en-us/dotnet/standard/base-types/custom-date-and-time-format-strings
    // FIX: ignore the sign, and digits after it
    int gmtIndicatorIndex = s.indexOf('+') == -1 ? s.indexOf('-') : s.indexOf('+');
    long l;
    if (gmtIndicatorIndex == -1) {
      l = Long.parseLong(s.substring(6, s.length() - 2));
    } else {
      l = Long.parseLong(s.substring(6, gmtIndicatorIndex));
    }

    Date d = new Date(l);
    return d;
  }
}).create();