diff --git a/lib/service/validators.dart b/lib/service/validators.dart
index aec3b9e..5743b40 100644
--- a/lib/service/validators.dart
+++ b/lib/service/validators.dart
@@ -7,6 +7,15 @@ String? timeValidator(String? value) {
   return 'Not a valid time format';
 }
 
+String? wholeNumberValidator(String? value) {
+  if (value == null || value.isEmpty) return null;
+
+  if (RegExp(r'^[0-9]*$').hasMatch(value)) {
+    return null;
+  }
+  return 'Not a valid number';
+}
+
 String? dateTimeValidator(String? value) {
   if (value == null || value.isEmpty) return null;