Fix RFC3339 serialization

rfctime/rfc3339.go

@@ -81,7 +81,7 @@ func (t *RFC3339Time) UnmarshalBSONValue(bt bsontype.Type, data []byte) error {
 		return errors.New(fmt.Sprintf("cannot unmarshal %v into RFC3339Time", bt))
 	}
 	var tt time.Time
-	err := bson.Unmarshal(data, &tt)
+	err := bson.RawValue{Type: bt, Value: data}.Unmarshal(&tt)
 	if err != nil {
 		return err
 	}
@@ -116,6 +116,12 @@ func (t RFC3339Time) DecodeValue(dc bsoncodec.DecodeContext, vr bsonrw.ValueRead
 		return err
 	}
 
+	if val.Kind() == reflect.Ptr {
+		val.Set(reflect.ValueOf(&t))
+	} else {
+		val.Set(reflect.ValueOf(t))
+	}
+
 	return nil
 }