2 files changed, 25 insertions, 0 deletions
diff --git a/internal/cli/liturgy.go b/internal/cli/liturgy.go
index fabac48..24052ab 100644
--- a/internal/cli/liturgy.go
+++ b/internal/cli/liturgy.go
@@ -23,6 +23,14 @@ func runLiturgy(cfg config.Config, date string, stdout, stderr io.Writer) int {
 		fmt.Fprintf(stderr, "lectio: bad date %q (want YYYY-MM-DD)\n", date)
 		return 2
 	}
+	// The computed engine currently does the Ordinary Form only. Rather than
+	// silently return OF for a traditional (EF) config, say so.
+	if cfg.Selection().Form == "old" {
+		fmt.Fprintln(stderr, "lectio: the offline calendar engine currently computes only the Ordinary Form.")
+		fmt.Fprintln(stderr, "        Traditional (1962 EF) computation is not built yet; your traditional daily")
+		fmt.Fprintln(stderr, "        readings still work via 'lectio [DATE]'. To compute the OF: add --lectionary new.")
+		return 1
+	}
 	dir, _ := config.CalendarsDir()
 	layers, errs := caldata.Stack(dir, cfg.Use)
 	for _, e := range errs {
diff --git a/internal/cli/liturgy_test.go b/internal/cli/liturgy_test.go
index c713703..02f02c4 100644
--- a/internal/cli/liturgy_test.go
+++ b/internal/cli/liturgy_test.go
@@ -33,6 +33,23 @@ func TestRunLiturgy(t *testing.T) {
 	}
 }
 
+func TestRunLiturgyTraditionalGuarded(t *testing.T) {
+	dir := t.TempDir()
+	t.Setenv("LECTIO_CONFIG", filepath.Join(dir, "config.ini"))
+	os.WriteFile(filepath.Join(dir, "config.ini"), []byte("lectionary = traditional\n"), 0o644)
+	cfg, err := config.Load()
+	if err != nil {
+		t.Fatal(err)
+	}
+	var buf bytes.Buffer
+	if code := runLiturgy(cfg, "2025-08-15", &buf, &buf); code == 0 {
+		t.Fatalf("traditional config should be guarded, not computed as OF:\n%s", buf.String())
+	}
+	if !strings.Contains(strings.ToLower(buf.String()), "ordinary form") {
+		t.Errorf("expected an EF-not-implemented notice:\n%s", buf.String())
+	}
+}
+
 func TestRunLiturgyUserLayer(t *testing.T) {
 	dir := t.TempDir()
 	t.Setenv("LECTIO_CONFIG", filepath.Join(dir, "config.ini"))