diff --git a/.claude/commands/version.md b/.claude/commands/version.md
index 07e8642..2c2dba8 100644
--- a/.claude/commands/version.md
+++ b/.claude/commands/version.md
@@ -33,8 +33,22 @@ Update ALL five version properties to the new value:
 
 #### 2. `docs/man/man1/keystone-cli.1`
 
-Update the VERSION section. Find the line that starts with `keystone-cli` under the
-`.Sh VERSION` section and update it to `keystone-cli X.Y.Z`.
+Update TWO sections in this file:
+
+**a) The `.Dd` date tag (line 1):**
+
+Run the locale-safe date script to get the current month and year:
+
+```bash
+./scripts/get-english-month-year.sh
+```
+
+Update the first line of the man page to `.Dd <output>` (e.g., `.Dd January 2026`).
+
+**b) The VERSION section:**
+
+Find the line that starts with `keystone-cli` under the `.Sh VERSION` section and
+update it to `keystone-cli X.Y.Z`.
 
 #### 3. `tests/Keystone.Cli.UnitTests/Application/Commands/Info/InfoCommandTests.cs`
 
diff --git a/scripts/get-english-month-year.sh b/scripts/get-english-month-year.sh
new file mode 100755
index 0000000..a7d4071
--- /dev/null
+++ b/scripts/get-english-month-year.sh
@@ -0,0 +1,29 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Returns the current month and year in English format: "Month YYYY"
+# This script is locale-independent and works on both macOS (BSD) and Linux (GNU).
+
+month_num=$(date '+%m')
+year=$(date '+%Y')
+
+case "$month_num" in
+  01) month_name="January" ;;
+  02) month_name="February" ;;
+  03) month_name="March" ;;
+  04) month_name="April" ;;
+  05) month_name="May" ;;
+  06) month_name="June" ;;
+  07) month_name="July" ;;
+  08) month_name="August" ;;
+  09) month_name="September" ;;
+  10) month_name="October" ;;
+  11) month_name="November" ;;
+  12) month_name="December" ;;
+  *)
+    echo "ERROR: Unexpected month number: $month_num" >&2
+    exit 1
+    ;;
+esac
+
+echo "${month_name} ${year}"
diff --git a/src/Keystone.Cli/Domain/CliInfo.cs b/src/Keystone.Cli/Domain/CliInfo.cs
new file mode 100644
index 0000000..ab75981
--- /dev/null
+++ b/src/Keystone.Cli/Domain/CliInfo.cs
@@ -0,0 +1,21 @@
+namespace Keystone.Cli.Domain;
+
+/// <summary>
+/// Metadata about the Keystone CLI application itself.
+/// </summary>
+public static class CliInfo
+{
+    /// <summary>
+    /// The year the Keystone CLI was created.
+    /// </summary>
+    public const int InceptionYear = 2025;
+
+    /// <summary>
+    /// The current year in local time.
+    /// </summary>
+    /// <remarks>
+    /// Uses local time to match the date script (<c>scripts/get-english-month-year.sh</c>),
+    /// which uses <c>date '+%Y'</c> (local time, not UTC).
+    /// </remarks>
+    public static int CurrentYear => DateTime.Now.Year;
+}
diff --git a/tests/Keystone.Cli.UnitTests/Docs/ManPageDateTagTests.cs b/tests/Keystone.Cli.UnitTests/Docs/ManPageDateTagTests.cs
new file mode 100644
index 0000000..aaf5ff1
--- /dev/null
+++ b/tests/Keystone.Cli.UnitTests/Docs/ManPageDateTagTests.cs
@@ -0,0 +1,75 @@
+using System.Text.RegularExpressions;
+using Keystone.Cli.Domain;
+using Keystone.Cli.UnitTests.TestUtilities;
+
+
+namespace Keystone.Cli.UnitTests.Docs;
+
+[TestFixture, Parallelizable(ParallelScope.All)]
+public partial class ManPageDateTagTests
+{
+    private static readonly string[] ValidEnglishMonths =
+    [
+        "January",
+        "February",
+        "March",
+        "April",
+        "May",
+        "June",
+        "July",
+        "August",
+        "September",
+        "October",
+        "November",
+        "December",
+    ];
+
+    [GeneratedRegex(@"^\.Dd ([A-Za-z]+) (\d{4})$")]
+    private static partial Regex DdTagPattern();
+
+    [Test]
+    public void ManPage_HasExactlyOneDdTag_WithValidEnglishMonthAndYear()
+    {
+        var manPagePath = GetManPagePath();
+        var lines = File.ReadAllLines(manPagePath);
+
+        var ddLines = lines
+            .Select((line, index) => (Line: line, LineNumber: index + 1))
+            .Where(x => x.Line.StartsWith(".Dd"))
+            .ToList();
+
+        Assert.That(ddLines, Has.Count.EqualTo(1), "Expected exactly one .Dd line in the man page");
+
+        var (ddLine, lineNumber) = ddLines[0];
+        var match = DdTagPattern().Match(ddLine);
+
+        Assert.That(
+            match.Success,
+            Is.True,
+            $"Line {lineNumber}: .Dd tag does not match expected pattern '.Dd Month YYYY'. Actual: '{ddLine}'"
+        );
+
+        var month = match.Groups[1].Value;
+        Assert.That(
+            ValidEnglishMonths,
+            Does.Contain(month),
+            $"Line {lineNumber}: Month '{month}' is not a valid English month name"
+        );
+
+        var year = int.Parse(match.Groups[2].Value);
+        Assert.That(
+            year,
+            Is.GreaterThanOrEqualTo(CliInfo.InceptionYear).And.LessThanOrEqualTo(CliInfo.CurrentYear),
+            $"Line {lineNumber}: Year {year} is outside reasonable range ({CliInfo.InceptionYear}-{CliInfo.CurrentYear})"
+        );
+    }
+
+    private static string GetManPagePath()
+    {
+        var manPagePath = Path.Combine(RepoPathResolver.GetRepoRoot(), "docs", "man", "man1", "keystone-cli.1");
+
+        return ! File.Exists(manPagePath)
+            ? throw new FileNotFoundException($"Man page not found at expected path: {manPagePath}")
+            : manPagePath;
+    }
+}
diff --git a/tests/Keystone.Cli.UnitTests/TestUtilities/RepoPathResolver.cs b/tests/Keystone.Cli.UnitTests/TestUtilities/RepoPathResolver.cs
new file mode 100644
index 0000000..268a2fb
--- /dev/null
+++ b/tests/Keystone.Cli.UnitTests/TestUtilities/RepoPathResolver.cs
@@ -0,0 +1,26 @@
+namespace Keystone.Cli.UnitTests.TestUtilities;
+
+/// <summary>
+/// Resolves paths relative to the repository root for tests that need to access repo files.
+/// </summary>
+public static class RepoPathResolver
+{
+    private const string SolutionFileName = "keystone-cli.sln";
+
+    /// <summary>
+    /// Finds the repository root by walking up from the test's base directory.
+    /// </summary>
+    /// <returns>The absolute path to the repository root.</returns>
+    /// <exception cref="InvalidOperationException">Thrown when the repository root cannot be found.</exception>
+    public static string GetRepoRoot()
+        => FindRepoRoot(new DirectoryInfo(AppContext.BaseDirectory))
+            ?? throw new InvalidOperationException("Could not find repository root. Ensure the test is running from within the repository.");
+
+    private static string? FindRepoRoot(DirectoryInfo? directory)
+        => directory switch
+        {
+            null => null,
+            _ when File.Exists(Path.Combine(directory.FullName, SolutionFileName)) => directory.FullName,
+            _ => FindRepoRoot(directory.Parent),
+        };
+}