CmdPal: Add calendar page to time/date dock band clock item

Clicking the time/date item in the CmdPal dock now opens a calendar
page showing the current month with today's date highlighted in bold.

- Add CalendarPage (ContentPage) that renders a markdown table calendar
  respecting the locale's first day of week and abbreviated day names
- Wire NowDockBand.Command to CalendarPage instead of NoOpCommand
- Add timedate_calendar_page_name resource string
- Add CalendarPageTests covering structure, today highlighting, and dock wiring

Co-authored-by: niels9001 <9866362+niels9001@users.noreply.github.com>
Agent-Logs-Url: https://github.com/microsoft/PowerToys/sessions/1d52e678-b258-441c-a409-1de12a42cb2a

src/modules/cmdpal/Tests/Microsoft.CmdPal.Ext.TimeDate.UnitTests/CalendarPageTests.cs

@@ -0,0 +1,138 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Globalization;
+using Microsoft.CmdPal.Ext.TimeDate.Pages;
+using Microsoft.CommandPalette.Extensions.Toolkit;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace Microsoft.CmdPal.Ext.TimeDate.UnitTests
+{
+    [TestClass]
+    public class CalendarPageTests
+    {
+        private CultureInfo originalCulture;
+        private CultureInfo originalUiCulture;
+
+        [TestInitialize]
+        public void Setup()
+        {
+            originalCulture = CultureInfo.CurrentCulture;
+            CultureInfo.CurrentCulture = new CultureInfo("en-us", false);
+            originalUiCulture = CultureInfo.CurrentUICulture;
+            CultureInfo.CurrentUICulture = new CultureInfo("en-us", false);
+        }
+
+        [TestCleanup]
+        public void Cleanup()
+        {
+            CultureInfo.CurrentCulture = originalCulture;
+            CultureInfo.CurrentUICulture = originalUiCulture;
+        }
+
+        [TestMethod]
+        public void CalendarPage_HasExpectedId()
+        {
+            var page = new CalendarPage();
+
+            Assert.AreEqual("com.microsoft.cmdpal.timedate.calendarPage", page.Id);
+        }
+
+        [TestMethod]
+        public void CalendarPage_HasNonEmptyName()
+        {
+            var page = new CalendarPage();
+
+            Assert.IsFalse(string.IsNullOrEmpty(page.Name));
+        }
+
+        [TestMethod]
+        public void GetContent_ReturnsOneMarkdownContent()
+        {
+            var page = new CalendarPage();
+
+            var content = page.GetContent();
+
+            Assert.IsNotNull(content);
+            Assert.AreEqual(1, content.Length);
+            Assert.IsInstanceOfType(content[0], typeof(MarkdownContent));
+        }
+
+        [TestMethod]
+        public void GetContent_TitleIsCurrentMonthAndYear()
+        {
+            var page = new CalendarPage();
+            page.GetContent();
+
+            var expected = DateTime.Now.ToString("MMMM yyyy", CultureInfo.CurrentCulture);
+
+            Assert.AreEqual(expected, page.Title);
+        }
+
+        [TestMethod]
+        public void GetContent_BodyContainsTodayBold()
+        {
+            var page = new CalendarPage();
+            var content = page.GetContent();
+
+            var markdown = content[0] as MarkdownContent;
+            var today = DateTime.Now.Day.ToString(CultureInfo.InvariantCulture);
+
+            Assert.IsTrue(markdown!.Body.Contains($"**{today}**"), "Today's day number should be bold in the calendar markdown.");
+        }
+
+        [TestMethod]
+        public void GetContent_BodyContainsDayHeaders()
+        {
+            var page = new CalendarPage();
+            var content = page.GetContent();
+
+            var markdown = content[0] as MarkdownContent;
+
+            // The body should contain abbreviated day names as column headers
+            var dayNames = CultureInfo.CurrentCulture.DateTimeFormat.AbbreviatedDayNames;
+            foreach (var dayName in dayNames)
+            {
+                Assert.IsTrue(markdown!.Body.Contains(dayName), $"Calendar should contain day header '{dayName}'.");
+            }
+        }
+
+        [TestMethod]
+        public void GetContent_BodyContainsAllDaysOfCurrentMonth()
+        {
+            var page = new CalendarPage();
+            var content = page.GetContent();
+
+            var markdown = content[0] as MarkdownContent;
+            var daysInMonth = DateTime.DaysInMonth(DateTime.Now.Year, DateTime.Now.Month);
+
+            for (var day = 1; day <= daysInMonth; day++)
+            {
+                Assert.IsTrue(markdown!.Body.Contains(day.ToString(CultureInfo.InvariantCulture)), $"Calendar should contain day {day}.");
+            }
+        }
+
+        [TestMethod]
+        public void GetDockBands_CommandIsCalendarPage()
+        {
+            var provider = new TimeDateCommandsProvider();
+
+            var bands = provider.GetDockBands();
+
+            Assert.IsNotNull(bands);
+            Assert.AreEqual(1, bands.Length);
+
+            // The band wraps a list; dig into its items to find the NowDockBand command.
+            var wrappedBand = bands[0] as WrappedDockItem;
+            Assert.IsNotNull(wrappedBand, "Dock band should be a WrappedDockItem.");
+
+            var items = wrappedBand.Items;
+            Assert.IsTrue(items.Length > 0, "Dock band should have at least one item.");
+
+            var command = items[0].Command;
+            Assert.IsInstanceOfType(command, typeof(CalendarPage), "The clock dock item's command should be a CalendarPage.");
+        }
+    }
+}

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.TimeDate/Pages/CalendarPage.cs

@@ -0,0 +1,99 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Globalization;
+using System.Text;
+using Microsoft.CommandPalette.Extensions.Toolkit;
+
+namespace Microsoft.CmdPal.Ext.TimeDate.Pages;
+
+internal sealed partial class CalendarPage : ContentPage
+{
+    public CalendarPage()
+    {
+        Id = "com.microsoft.cmdpal.timedate.calendarPage";
+        Name = Resources.timedate_calendar_page_name;
+        Icon = Icons.TimeDateExtIcon;
+    }
+
+    public override IContent[] GetContent()
+    {
+        var now = DateTime.Now;
+        Title = now.ToString("MMMM yyyy", CultureInfo.CurrentCulture);
+        return [new MarkdownContent(GenerateCalendarMarkdown(now))];
+    }
+
+    private static string GenerateCalendarMarkdown(DateTime now)
+    {
+        var sb = new StringBuilder();
+        var culture = CultureInfo.CurrentCulture;
+        var firstDayOfMonth = new DateTime(now.Year, now.Month, 1);
+        var daysInMonth = DateTime.DaysInMonth(now.Year, now.Month);
+        var firstDayOfWeek = culture.DateTimeFormat.FirstDayOfWeek;
+        var abbreviatedDayNames = culture.DateTimeFormat.AbbreviatedDayNames;
+
+        // Header row: abbreviated day names starting from the culture's first day of week
+        sb.Append('|');
+        for (var i = 0; i < 7; i++)
+        {
+            var dayIndex = ((int)firstDayOfWeek + i) % 7;
+            sb.Append($" {abbreviatedDayNames[dayIndex]} |");
+        }
+
+        sb.AppendLine();
+
+        // Separator
+        sb.Append('|');
+        for (var i = 0; i < 7; i++)
+        {
+            sb.Append(":-:|");
+        }
+
+        sb.AppendLine();
+
+        // Calculate how many blank cells appear before day 1
+        var firstDayDow = (int)firstDayOfMonth.DayOfWeek;
+        var offset = ((firstDayDow - (int)firstDayOfWeek) + 7) % 7;
+
+        sb.Append('|');
+        for (var i = 0; i < offset; i++)
+        {
+            sb.Append("   |");
+        }
+
+        var col = offset;
+        for (var day = 1; day <= daysInMonth; day++)
+        {
+            if (day == now.Day)
+            {
+                sb.Append($" **{day}** |");
+            }
+            else
+            {
+                sb.Append($" {day} |");
+            }
+
+            col++;
+
+            if (col == 7 && day < daysInMonth)
+            {
+                sb.AppendLine();
+                sb.Append('|');
+                col = 0;
+            }
+        }
+
+        // Pad the last row with empty cells
+        while (col > 0 && col < 7)
+        {
+            sb.Append("   |");
+            col++;
+        }
+
+        sb.AppendLine();
+
+        return sb.ToString();
+    }
+}

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.TimeDate/Properties/Resources.Designer.cs

@@ -959,5 +959,14 @@ namespace Microsoft.CmdPal.Ext.TimeDate {
                 return ResourceManager.GetString("timedate_copy_time_command_name", resourceCulture);
             }
         }
+        
+        /// <summary>
+        ///   Looks up a localized string similar to Calendar.
+        /// </summary>
+        public static string timedate_calendar_page_name {
+            get {
+                return ResourceManager.GetString("timedate_calendar_page_name", resourceCulture);
+            }
+        }
     }
 }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.TimeDate/Properties/Resources.resx

@@ -444,4 +444,8 @@
     <value>Copy date</value>
     <comment>Name of a command to copy the current date to the clipboard</comment>
   </data>
+  <data name="timedate_calendar_page_name" xml:space="preserve">
+    <value>Calendar</value>
+    <comment>Name of the calendar page shown when clicking the clock in the dock</comment>
+  </data>
 </root>

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.TimeDate/TimeDateCommandsProvider.cs

@@ -75,7 +75,7 @@ internal sealed partial class NowDockBand : ListItem
 
     public NowDockBand()
     {
-        Command = new NoOpCommand() { Id = "com.microsoft.cmdpal.timedate.dockBand" };
+        Command = new CalendarPage();
         _copyTimeCommand = new CopyTextCommand(string.Empty) { Name = Resources.timedate_copy_time_command_name };
         _copyDateCommand = new CopyTextCommand(string.Empty) { Name = Resources.timedate_copy_date_command_name };
         MoreCommands = [