Human-readable game "Timestamp".

UndertaleModTool/Editors/UndertaleGeneralInfoEditor.xaml

@@ -15,6 +15,7 @@
         <local:BooleanToVisibilityConverter x:Key="BooleanFalseToVisibilityConverter" local:trueValue="Collapsed" local:falseValue="Visible"/>
         <local:ByteArrayConverter x:Key="byteArrayConverter"/>
         <local:ByteGUIDArrayConverter x:Key="byteGUIDArrayConverter"/>
+        <local:TimestampDateTimeConverter x:Key="TimestampDateTimeConverter"/>
     </UserControl.Resources>
 
     <StackPanel>
@@ -125,7 +126,19 @@
                 <TextBox Grid.Row="14" Grid.Column="1" Margin="3" Text="{Binding GeneralInfo.LicenseCRC32, StringFormat={}{0:X8}}"/>
 
                 <TextBlock Grid.Row="15" Grid.Column="0" Margin="3">Timestamp</TextBlock>
-                <TextBox Grid.Row="15" Grid.Column="1" Margin="3" Text="{Binding GeneralInfo.Timestamp}"/>
+                <TextBox Grid.Row="15" Grid.Column="1" Margin="3" IsReadOnly="True"
+                         Text="{Binding GeneralInfo.Timestamp, Mode=OneWay, Converter={StaticResource TimestampDateTimeConverter}}"
+                         ToolTip="{Binding GeneralInfo.Timestamp, Mode=OneWay, Converter={StaticResource TimestampDateTimeConverter}, ConverterParameter=GMT}"
+                         ToolTipService.InitialShowDelay="250">
+                    <TextBox.Background>
+                        <VisualBrush AlignmentX="Right" AlignmentY="Center" Stretch="None">
+                            <VisualBrush.Visual>
+                                <Label Content="(local time, hover to see GMT+0)"
+                                       Foreground="Gray" FontStyle="Italic" Margin="0,0,5,0"/>
+                            </VisualBrush.Visual>
+                        </VisualBrush>
+                    </TextBox.Background>
+                </TextBox>
 
                 <TextBlock Grid.Row="16" Grid.Column="0" Margin="3">Display name</TextBlock>
                 <local:UndertaleStringReference Grid.Row="16" Grid.Column="1" Margin="3" ObjectReference="{Binding GeneralInfo.DisplayName}"/>

UndertaleModTool/Editors/UndertaleGeneralInfoEditor.xaml.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
@@ -36,4 +37,28 @@ private void SyncRoomList_Click(object sender, RoutedEventArgs e)
                 roomOrder.Add(new UndertaleResourceById<UndertaleRoom, UndertaleChunkROOM>() { Resource = room });
         }
     }
+
+    public class TimestampDateTimeConverter : IValueConverter
+    {
+        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            if (value is not ulong timestamp)
+                return "(error)";
+            DateTimeOffset dateTimeOffset = DateTimeOffset.FromUnixTimeSeconds((long)timestamp);
+            if (parameter is string par && par == "GMT")
+                return "GMT+0: " + dateTimeOffset.UtcDateTime.ToString();
+            else
+                return dateTimeOffset.LocalDateTime.ToString();
+        }
+
+        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            if (value is not string dateTimeStr)
+                return new ValidationResult(false, "The value is not a string.");
+            if (!DateTime.TryParse(dateTimeStr, out DateTime dateTime))
+                return new ValidationResult(false, "Invalid date time format.");
+
+            return (ulong)(new DateTimeOffset(dateTime).ToUnixTimeSeconds());
+        }
+    }
 }