diff --git a/Elwig/Helpers/Validator.cs b/Elwig/Helpers/Validator.cs
index aa99de6..064572d 100644
--- a/Elwig/Helpers/Validator.cs
+++ b/Elwig/Helpers/Validator.cs
@@ -521,6 +521,36 @@ namespace Elwig.Helpers {
             return new(true, null);
         }
 
+        public static ValidationResult CheckTime(TextBox input, bool required) {
+            string text = "";
+            int pos = input.CaretIndex;
+            int v = 0;
+            for (int i = 0; i < input.Text.Length; i++) {
+                char ch = input.Text[i];
+                if (v >= 0 && v < 5 && v != 2 && char.IsAsciiDigit(ch)) {
+                    if ((v == 0 && ch <= '2') || (v == 1 && (text[0] < '2' || ch <= '3')) || (v == 3 && ch <= '5') || v == 4) {
+                        text += ch;
+                        v++;
+                    }
+                } else if (v == 2 && ch == ':') {
+                    text += ch;
+                    v++;
+                }
+                if (i == input.CaretIndex - 1)
+                    pos = text.Length;
+            }
+            input.Text = text;
+            input.CaretIndex = pos;
+
+            if (text.Length == 0) {
+                return required ? new(false, "Wert ist nicht optional") : new(true, null);
+            } else if (v != 5) {
+                return new(false, "Zeit ist ungültig");
+            } else {
+                return new(true, null);
+            }
+        }
+
         public static ValidationResult CheckFbNr(TextBox input, bool required, AppDbContext ctx, AreaCom? c) {
             var res = CheckInteger(input, required);
             if (!res.IsValid) {
diff --git a/Elwig/Windows/AdministrationWindow.cs b/Elwig/Windows/AdministrationWindow.cs
index 5630c09..6b06f3a 100644
--- a/Elwig/Windows/AdministrationWindow.cs
+++ b/Elwig/Windows/AdministrationWindow.cs
@@ -482,6 +482,14 @@ namespace Elwig.Windows {
             InputLostFocus((TextBox)sender, Validator.CheckDate);
         }
 
+        protected void TimeInput_TextChanged(object sender, RoutedEventArgs evt) {
+            InputTextChanged((TextBox)sender, Validator.CheckTime);
+        }
+
+        protected void TimeInput_LostFocus(object sender, RoutedEventArgs evt) {
+            InputLostFocus((TextBox)sender, Validator.CheckTime);
+        }
+
         protected void PlzInput_TextChanged(object sender, RoutedEventArgs evt) {
             var plz = (TextBox)sender;
             InputTextChanged(plz, Validator.CheckPlz);
diff --git a/Elwig/Windows/DeliveryAdminWindow.xaml b/Elwig/Windows/DeliveryAdminWindow.xaml
index 0fa822e..edcec92 100644
--- a/Elwig/Windows/DeliveryAdminWindow.xaml
+++ b/Elwig/Windows/DeliveryAdminWindow.xaml
@@ -72,6 +72,10 @@
             <MenuItem Header="Exportieren">
                 <MenuItem x:Name="Menu_Export_Bki" Header="Traubentransportscheinliste (BKI)"/>
             </MenuItem>
+            <MenuItem Header="Einstellungen">
+                <MenuItem x:Name="Menu_Settings_EnableFreeEditing" Header="Freie Bearbeitung aktivieren"
+                          IsCheckable="True" Checked="Menu_Settings_EnableFreeEditing_Checked" Unchecked="Menu_Settings_EnableFreeEditing_Unchecked"/>
+            </MenuItem>
         </Menu>
 
         <Grid Grid.Row="1" Margin="5,0,0,0">
@@ -228,18 +232,21 @@
 
                     <Label Content="LieferscheinNr.:" Margin="10,10,0,0" Grid.Column="0"/>
                     <TextBox x:Name="LsNrInput" Width="126" Grid.Column="1" HorizontalAlignment="Left" Margin="0,10,0,0"
-                             IsReadOnly="True" IsTabStop="False"/>
+                             IsReadOnly="True" IsTabStop="False"
+                             TextChanged="TextBox_TextChanged"/>
 
                     <Label Content="Datum/Uhrzeit:" Margin="10,40,0,0" Grid.Column="0"/>
                     <TextBox x:Name="DateInput" Width="77" Grid.Column="1" HorizontalAlignment="Left" Margin="0,40,0,0"
-                             IsReadOnly="True" IsTabStop="False"
-                             TextChanged="DateInput_TextChanged"/>
+                             IsReadOnly="True"
+                             TextChanged="DateInput_TextChanged" LostFocus="DateInput_LostFocus"/>
                     <TextBox x:Name="TimeInput" Width="44" Grid.Column="1" HorizontalAlignment="Left" Margin="82,40,0,0"
-                             IsReadOnly="True" IsTabStop="False"/>
+                             IsReadOnly="True"
+                             TextChanged="TimeInput_TextChanged" LostFocus="TimeInput_LostFocus"/>
 
                     <Label Content="Zweigstelle:" Margin="10,70,0,0" Grid.Column="0"/>
                     <ComboBox x:Name="BranchInput" Width="126" Margin="0,70,10,0" Grid.Column="1" HorizontalAlignment="Left"
                               IsEnabled="False"
+                              SelectionChanged="BranchInput_SelectionChanged"
                               DisplayMemberPath="Name" TextSearch.TextPath="Name"/>
 
                     <Label Content="Anmerkung:" Margin="10,100,0,10"/>
diff --git a/Elwig/Windows/DeliveryAdminWindow.xaml.cs b/Elwig/Windows/DeliveryAdminWindow.xaml.cs
index d2b943a..e6fe21e 100644
--- a/Elwig/Windows/DeliveryAdminWindow.xaml.cs
+++ b/Elwig/Windows/DeliveryAdminWindow.xaml.cs
@@ -180,11 +180,30 @@ namespace Elwig.Windows {
             doc.Show();
         }
 
+        private void Menu_Settings_EnableFreeEditing_Checked(object sender, RoutedEventArgs evt) {
+            if (IsEditing || IsCreating) {
+                DateInput.IsReadOnly = false;
+                TimeInput.IsReadOnly = false;
+                BranchInput.IsEnabled = true;
+                if (IsCreating) TimeInput.Text = "";
+                OnSecondPassed(null, null);
+            }
+        }
+
+        private void Menu_Settings_EnableFreeEditing_Unchecked(object sender, RoutedEventArgs evt) {
+            DateInput.IsReadOnly = true;
+            TimeInput.IsReadOnly = true;
+            BranchInput.IsEnabled = false;
+            OnSecondPassed(null, null);
+        }
+
         private void OnSecondPassed(object? sender, EventArgs? evt) {
-            if (IsReceipt && IsCreating) {
+            if (IsReceipt && IsCreating && !Menu_Settings_EnableFreeEditing.IsChecked) {
                 var now = DateTime.Now;
                 TimeInput.Text = now.ToString("HH:mm");
                 DateInput.Text = now.ToString("dd.MM.yyyy");
+                SetDefaultValue(TimeInput);
+                SetDefaultValue(DateInput);
             }
         }
 
@@ -663,10 +682,10 @@ namespace Elwig.Windows {
             if (deliveryNew || InputHasChanged(DateInput)) {
                 d.LNr = await Context.NextLNr(d.Date);
             }
-            if (IsCreating) {
+            if (IsCreating && !InputIsNotDefault(TimeInput)) {
                 d.TimeString = DateTime.Now.ToString("HH:mm:ss");
-            } else if (InputHasChanged(TimeInput)) {
-                d.TimeString = TimeInput.Text + ":00";
+            } else if (IsCreating || InputHasChanged(TimeInput)) {
+                d.TimeString = (TimeInput.Text != "") ? TimeInput.Text + ":00" : null;
             }
             d.ZwstId = (BranchInput.SelectedItem as Branch)?.ZwstId;
             d.LsNr = LsNrInput.Text;
@@ -1269,9 +1288,9 @@ namespace Elwig.Windows {
             AbgewertetInput.IsEnabled = false;
             ManualWeighingInput.IsEnabled = false;
             LsNrInput.IsReadOnly = true;
-            DateInput.IsReadOnly = true;
-            TimeInput.IsReadOnly = true;
-            BranchInput.IsEnabled = false;
+            DateInput.IsReadOnly = !Menu_Settings_EnableFreeEditing.IsChecked;
+            TimeInput.IsReadOnly = !Menu_Settings_EnableFreeEditing.IsChecked;
+            BranchInput.IsEnabled = Menu_Settings_EnableFreeEditing.IsChecked;
         }
 
         private void DisableWeighingButtons() {
@@ -1295,15 +1314,25 @@ namespace Elwig.Windows {
             if (DateInput.Text == "" || BranchInput.SelectedItem == null) {
                 LsNrInput.Text = "";
             } else {
-                var branch = (Branch)BranchInput.SelectedItem;
-                var date = DateOnly.ParseExact(DateInput.Text, "dd.MM.yyyy");
-                var lnr = await Context.NextLNr(date);
-                LsNrInput.Text = Utils.GenerateLsNr(date, branch.ZwstId, lnr);
+                try {
+                    var branch = (Branch)BranchInput.SelectedItem;
+                    var date = DateOnly.ParseExact(DateInput.Text, "dd.MM.yyyy");
+                    var lnr = await Context.NextLNr(date);
+                    LsNrInput.Text = Utils.GenerateLsNr(date, branch.ZwstId, lnr);
+                } catch {
+                    LsNrInput.Text = "";
+                }
             }
         }
 
         private void DateInput_TextChanged(object sender, TextChangedEventArgs evt) {
-            if (IsCreating) UpdateLsNr().GetAwaiter().GetResult();
+            base.DateInput_TextChanged(sender, evt);
+            if (IsEditing ||  IsCreating) UpdateLsNr().GetAwaiter().GetResult();
+        }
+
+        private void BranchInput_SelectionChanged(object sender, RoutedEventArgs evt) {
+            base.ComboBox_SelectionChanged(sender, evt);
+            if (IsEditing || IsCreating) UpdateLsNr().GetAwaiter().GetResult();
         }
 
         private void UpdateWineVariety(bool valid) {