diff --git a/src/stores/mixin.ts b/src/stores/mixin.ts
index 48ca0e791..16df8875c 100644
--- a/src/stores/mixin.ts
+++ b/src/stores/mixin.ts
@@ -915,6 +915,13 @@ export const useCounterMixin = defineStore("mixin", () => {
     return "";
   }
 
+  function diffDay(startDate: any, endDate: any) {
+    var d1 = moment(startDate);
+    var d2 = moment(endDate);
+    const daydiff = Math.ceil(moment.duration(d2.diff(d1)).asDays());
+    return daydiff;
+  }
+
   return {
     calAge,
     date2Thai,
@@ -951,5 +958,6 @@ export const useCounterMixin = defineStore("mixin", () => {
     fails,
     convertDate,
     convertDateDisplay,
+    diffDay,
   };
 });