diff --git a/project/ui/app.slint b/project/ui/app.slint
index 3506212..e3f19de 100644
--- a/project/ui/app.slint
+++ b/project/ui/app.slint
@@ -1,6 +1,12 @@
 import { DatePickerPopup, Button, VerticalBox, HorizontalBox, ComboBox } from "std-widgets.slint";
 import { Calculation } from "calculation.slint";
 
+export struct CalcResult {
+    message: string,
+    start: int,
+    end: int,
+}
+
 export component Prorater inherits Window {
     title: "Auto Spa Express - Prorater";
     width: 1024px;