fix error Invalid time value

src/interfaces/extension.ts

@@ -300,6 +300,9 @@ class Extension {
   }
 
   public static CalculateAge(appointDate: Date, plusYear: number = 0, subtractYear: number = 0) {
+    if (appointDate == null || appointDate == undefined) return 0;
+    // Check for Invalid Date
+    if (isNaN(appointDate.getTime())) return 0;
     let currentDate = new Date().getTime();
     let appointDateTime = new Date(appointDate).getTime();
     let ageInMilliseconds = currentDate - appointDateTime;