Fixed age calculator visibility

Reviewed-on: #184

ui/src/components/application/ApplicationForm.vue

@@ -110,14 +110,17 @@ watch(() => showCoC.value, async () => {
 });
 
 function convertToAge(dob: string) {
+
+  if (dob === undefined) return "";
   const [month, day, year] = dob.split('/').map(Number);
 
   let dobDate = new Date(year, month - 1, day);
 
-  return Math.floor(
+  let out = Math.floor(
     (Date.now() - dobDate.getTime()) / (1000 * 60 * 60 * 24 * 365.2425)
   );
 
+  return Number.isNaN(out) ? "" : out;
 }
 
 </script>
@@ -132,7 +135,7 @@ function convertToAge(dob: string) {
         <FormControl>
           <template class="flex items-center gap-10">
             <DateInput :model-value="(value as string) ?? ''" :disabled="readOnly" @update:model-value="handleChange" />
-            <p class="text-muted-foreground">Age: {{ convertToAge(value) }}</p>
+            <p v-if="props.readOnly" class="text-muted-foreground">Age: {{ convertToAge(value) }}</p>
           </template>
         </FormControl>
         <div class="h-4">