diff --git a/Elwig/Windows/PaymentVariantsWindow.xaml b/Elwig/Windows/PaymentVariantsWindow.xaml
index d3b8a56..ff7fe19 100644
--- a/Elwig/Windows/PaymentVariantsWindow.xaml
+++ b/Elwig/Windows/PaymentVariantsWindow.xaml
@@ -140,8 +140,9 @@
             <TextBox x:Name="CommentInput" Grid.Column="1" HorizontalAlignment="Stretch" Margin="0,40,10,0"
                      TextChanged="CommentInput_TextChanged"/>
 
-            <Label Content="Erstellt am:" Margin="10,70,0,0" Grid.Column="0"/>
-            <TextBox x:Name="DateInput" Grid.Column="1" Width="77" HorizontalAlignment="Left" Margin="0,70,10,0" IsReadOnly="True"/>
+            <Label Content="Datum:" Margin="10,70,0,0" Grid.Column="0"/>
+            <TextBox x:Name="DateInput" Grid.Column="1" Width="77" HorizontalAlignment="Left" Margin="0,70,10,0"
+                     TextChanged="DateInput_TextChanged"/>
 
             <Label Content="Überwiesen am:" Margin="10,100,0,0" Grid.Column="0"/>
             <TextBox x:Name="TransferDateInput" Grid.Column="1" Width="77" HorizontalAlignment="Left" Margin="0,100,10,0"
diff --git a/Elwig/Windows/PaymentVariantsWindow.xaml.cs b/Elwig/Windows/PaymentVariantsWindow.xaml.cs
index 0377ac3..b3006bc 100644
--- a/Elwig/Windows/PaymentVariantsWindow.xaml.cs
+++ b/Elwig/Windows/PaymentVariantsWindow.xaml.cs
@@ -19,7 +19,7 @@ namespace Elwig.Windows {
 
         public readonly int Year;
         public readonly bool SeasonLocked;
-        private bool DataValid, DataChanged, NameChanged, CommentChanged, TransferDateValid, TransferDateChanged;
+        private bool DataValid, DataChanged, NameChanged, CommentChanged, DateValid, DateChanged, TransferDateValid, TransferDateChanged;
         private BillingData? BillingData;
         private bool WeightModifierChanged = false;
 
@@ -175,6 +175,7 @@ namespace Elwig.Windows {
         private void UpdateSaveButton() {
             SaveButton.IsEnabled = PaymentVariantList.SelectedItem != null &&
                 ((DataChanged && DataValid) || NameChanged || CommentChanged ||
+                (DateChanged && DateValid) ||
                 (TransferDateChanged && TransferDateValid) ||
                 (ConsiderModifiersInput.IsChecked != BillingData?.ConsiderDelieryModifiers) ||
                 (ConsiderPenaltiesInput.IsChecked != BillingData?.ConsiderContractPenalties) ||
@@ -495,6 +496,7 @@ namespace Elwig.Windows {
             try {
                 v.Name = NameInput.Text;
                 v.Comment = (CommentInput.Text != "") ? CommentInput.Text : null;
+                v.DateString = string.Join("-", DateInput.Text.Split(".").Reverse());
                 v.TransferDateString = (TransferDateInput.Text != "") ? string.Join("-", TransferDateInput.Text.Split(".").Reverse()) : null;
                 var d = App.Config.Debug ? BillingData.FromJson(DataInput.Text) : BillingData;
                 d.ConsiderDelieryModifiers = ConsiderModifiersInput.IsChecked ?? false;
@@ -563,6 +565,27 @@ namespace Elwig.Windows {
             UpdateSaveButton();
         }
 
+        private void DateInput_TextChanged(object sender, TextChangedEventArgs evt) {
+            if (PaymentVariantList.SelectedItem is not PaymentVar v) {
+                ControlUtils.ClearInputState(DateInput);
+                return;
+            }
+            var res = Validator.CheckDate(DateInput, true);
+            if (!res.IsValid) {
+                ControlUtils.SetInputInvalid(DateInput);
+                DateValid = false;
+            } else if (DateInput.Text != $"{v.Date:dd.MM.yyyy}") {
+                ControlUtils.SetInputChanged(DateInput);
+                DateValid = true;
+                DateChanged = true;
+            } else {
+                ControlUtils.ClearInputState(DateInput);
+                DateValid = true;
+                DateChanged = false;
+            }
+            UpdateSaveButton();
+        }
+
         private void TransferDateInput_TextChanged(object sender, TextChangedEventArgs evt) {
             if (PaymentVariantList.SelectedItem is not PaymentVar v) {
                 ControlUtils.ClearInputState(TransferDateInput);