diff --git a/lib/mix/tasks/totp_diagnose.exs b/lib/mix/tasks/totp_diagnose.exs
new file mode 100644
index 00000000..5268daa3
--- /dev/null
+++ b/lib/mix/tasks/totp_diagnose.exs
@@ -0,0 +1,126 @@
+defmodule Mix.Tasks.Totp.Diagnose do
+  @shortdoc "Diagnose TOTP verification failures"
+
+  @moduledoc """
+  Diagnostic tool for TOTP verification failures.
+
+  Usage:
+      mix totp.diagnose <user_email> <provided_code> <server_unix_timestamp>
+
+  Example:
+      mix totp.diagnose user@example.com 776330 1769641093
+
+  This will:
+  1. Check if the provided code matches the user's secret at any time within ±24 hours
+  2. Report the exact time offset if found
+  3. Help identify if the issue is clock drift or secret mismatch
+  """
+
+  use Mix.Task
+
+  require Logger
+
+  def run(args) do
+    Mix.Task.run("app.start")
+
+    case args do
+      [email, provided_code, timestamp_str] ->
+        diagnose(email, provided_code, String.to_integer(timestamp_str))
+
+      _ ->
+        IO.puts("""
+        Usage: mix totp.diagnose <user_email> <provided_code> <server_unix_timestamp>
+
+        Example:
+            mix totp.diagnose user@example.com 776330 1769641093
+        """)
+    end
+  end
+
+  defp diagnose(email, provided_code, server_timestamp) do
+    IO.puts("\n=== TOTP Diagnostic Tool ===\n")
+    IO.puts("Email: #{email}")
+    IO.puts("Provided code: #{provided_code}")
+    IO.puts("Server time: #{DateTime.from_unix!(server_timestamp)} (unix: #{server_timestamp})")
+
+    user = Towerops.Accounts.get_user_by_email(email)
+
+    if is_nil(user) do
+      IO.puts("\n❌ User not found!")
+      exit({:shutdown, 1})
+    end
+
+    if is_nil(user.totp_secret) do
+      IO.puts("\n❌ User does not have TOTP enabled!")
+      exit({:shutdown, 1})
+    end
+
+    IO.puts("\nTOTP enabled: Yes")
+    IO.puts("Secret length: #{byte_size(user.totp_secret)} bytes")
+
+    # Check current expected codes
+    IO.puts("\n--- Expected codes at failure time ---")
+    expected_current = NimbleTOTP.verification_code(user.totp_secret, time: server_timestamp)
+    expected_prev = NimbleTOTP.verification_code(user.totp_secret, time: server_timestamp - 30)
+    expected_next = NimbleTOTP.verification_code(user.totp_secret, time: server_timestamp + 30)
+
+    IO.puts("Current window: #{expected_current}")
+    IO.puts("Previous (-30s): #{expected_prev}")
+    IO.puts("Next (+30s): #{expected_next}")
+
+    # Search for when the provided code would have been valid
+    IO.puts("\n--- Searching for provided code in wider time window ---")
+    IO.puts("Scanning ±24 hours (2880 time steps)...")
+
+    found_time = search_for_code(user.totp_secret, provided_code, server_timestamp)
+
+    if found_time do
+      offset_seconds = found_time - server_timestamp
+      offset_minutes = Float.round(offset_seconds / 60, 1)
+
+      IO.puts("\n✓ FOUND! The provided code was valid at:")
+      IO.puts("  Time: #{DateTime.from_unix!(found_time)}")
+      IO.puts("  Offset: #{offset_seconds} seconds (#{offset_minutes} minutes)")
+
+      cond do
+        abs(offset_seconds) <= 120 ->
+          IO.puts("\n⚠️  This should have been accepted (within ±2 minute window)")
+          IO.puts("   Possible bug in verification logic!")
+
+        abs(offset_seconds) <= 900 ->
+          IO.puts("\n⏰ Clock drift detected: #{abs(offset_minutes)} minutes")
+          IO.puts("   The client's clock is off by more than 2 minutes.")
+
+        true ->
+          IO.puts("\n⏰ Extreme clock drift: #{abs(offset_minutes)} minutes")
+          IO.puts("   The client's clock is significantly incorrect.")
+      end
+    else
+      IO.puts("\n❌ NOT FOUND in ±24 hour window")
+      IO.puts("\nThis strongly suggests a SECRET MISMATCH:")
+      IO.puts("  - The secret in the database differs from what's in the authenticator app")
+      IO.puts("  - The user may have scanned a different QR code")
+      IO.puts("  - The secret may have been regenerated without updating the authenticator")
+      IO.puts("\nRecommended action:")
+      IO.puts("  1. Have the user disable TOTP")
+      IO.puts("  2. Re-enable TOTP and scan the new QR code")
+      IO.puts("  3. Verify the new code works before proceeding")
+    end
+
+    IO.puts("\n")
+  end
+
+  defp search_for_code(secret, provided_code, server_timestamp) do
+    # Check ±24 hours (86400 seconds = 2880 time steps of 30 seconds)
+    time_steps = 2880
+
+    Enum.find_value(-time_steps..time_steps, fn step ->
+      test_time = server_timestamp + step * 30
+      expected = NimbleTOTP.verification_code(secret, time: test_time)
+
+      if expected == provided_code do
+        test_time
+      end
+    end)
+  end
+end
diff --git a/lib/mix/tasks/totp_time_check.exs b/lib/mix/tasks/totp_time_check.exs
new file mode 100644
index 00000000..99ee1488
--- /dev/null
+++ b/lib/mix/tasks/totp_time_check.exs
@@ -0,0 +1,75 @@
+defmodule Mix.Tasks.Totp.TimeCheck do
+  @shortdoc "Check server time and TOTP time synchronization"
+
+  @moduledoc """
+  Diagnostic tool to check if the server's clock is correct.
+
+  Usage:
+      mix totp.time_check
+
+  This will:
+  1. Show the server's current time (BEAM VM time)
+  2. Show the system's current time
+  3. Calculate what TOTP codes should be valid right now for a test secret
+  """
+
+  use Mix.Task
+
+  require Logger
+
+  def run(_args) do
+    Mix.Task.run("app.start")
+
+    IO.puts("\n=== Time Synchronization Check ===\n")
+
+    # Get different time sources
+    system_time = System.system_time(:second)
+    os_time = :os.system_time(:second)
+    datetime_now = DateTime.utc_now()
+
+    IO.puts("System.system_time(:second): #{system_time}")
+    IO.puts("  → #{DateTime.from_unix!(system_time)}")
+    IO.puts("")
+    IO.puts(":os.system_time(:second): #{os_time}")
+    IO.puts("  → #{DateTime.from_unix!(os_time)}")
+    IO.puts("")
+    IO.puts("DateTime.utc_now(): #{datetime_now}")
+    IO.puts("  → unix: #{DateTime.to_unix(datetime_now)}")
+    IO.puts("")
+
+    # Check if they match
+    if system_time == os_time and system_time == DateTime.to_unix(datetime_now) do
+      IO.puts("✓ All time sources agree")
+    else
+      IO.puts("⚠️  WARNING: Time sources disagree!")
+      IO.puts("  System vs OS diff: #{system_time - os_time} seconds")
+      IO.puts("  System vs DateTime diff: #{system_time - DateTime.to_unix(datetime_now)} seconds")
+    end
+
+    IO.puts("")
+
+    # Show what TOTP codes would be generated now
+    test_secret = NimbleTOTP.secret()
+    current_code = NimbleTOTP.verification_code(test_secret, time: system_time)
+    prev_code = NimbleTOTP.verification_code(test_secret, time: system_time - 30)
+    next_code = NimbleTOTP.verification_code(test_secret, time: system_time + 30)
+
+    IO.puts("Test TOTP codes (with random secret):")
+    IO.puts("  Current window: #{current_code}")
+    IO.puts("  Previous (-30s): #{prev_code}")
+    IO.puts("  Next (+30s): #{next_code}")
+    IO.puts("")
+
+    # Recommend action
+    IO.puts("=== Recommendations ===")
+    IO.puts("")
+    IO.puts("Compare the server time above with actual UTC time:")
+    IO.puts("  Current actual UTC: Run 'date -u' on your local machine")
+    IO.puts("")
+    IO.puts("If the server time is wrong:")
+    IO.puts("  1. Check K8s node time: kubectl exec -it <pod> -- date -u")
+    IO.puts("  2. Check if NTP is running on the node")
+    IO.puts("  3. Restart the pod to resync time")
+    IO.puts("")
+  end
+end
diff --git a/lib/towerops_web/controllers/health_controller.ex b/lib/towerops_web/controllers/health_controller.ex
index 579188f9..1d88e1b7 100644
--- a/lib/towerops_web/controllers/health_controller.ex
+++ b/lib/towerops_web/controllers/health_controller.ex
@@ -78,4 +78,29 @@ defmodule ToweropsWeb.HealthController do
   defp redis_status_string(:ok), do: "connected"
   defp redis_status_string(:error), do: "disconnected"
   defp redis_status_string(:not_configured), do: "not_configured"
+
+  @doc """
+  Time diagnostic endpoint for debugging TOTP issues.
+  Returns server time from multiple sources.
+  """
+  def time(conn, _params) do
+    system_time = System.system_time(:second)
+    os_time = :os.system_time(:second)
+    datetime_now = DateTime.utc_now()
+
+    conn
+    |> put_resp_content_type("application/json")
+    |> send_resp(
+      200,
+      Jason.encode!(%{
+        system_time: system_time,
+        system_time_iso: system_time |> DateTime.from_unix!() |> DateTime.to_iso8601(),
+        os_time: os_time,
+        os_time_iso: os_time |> DateTime.from_unix!() |> DateTime.to_iso8601(),
+        datetime_now: DateTime.to_unix(datetime_now),
+        datetime_now_iso: DateTime.to_iso8601(datetime_now),
+        time_sources_agree: system_time == os_time and system_time == DateTime.to_unix(datetime_now)
+      })
+    )
+  end
 end
diff --git a/lib/towerops_web/router.ex b/lib/towerops_web/router.ex
index 18d7cc4a..42e9b16e 100644
--- a/lib/towerops_web/router.ex
+++ b/lib/towerops_web/router.ex
@@ -39,6 +39,7 @@ defmodule ToweropsWeb.Router do
   # Health check endpoint for Kubernetes probes (no authentication required)
   scope "/", ToweropsWeb do
     get "/health", HealthController, :index
+    get "/health/time", HealthController, :time
   end
 
   scope "/", ToweropsWeb do