Say so when the day asked about is out of reach

cmd/mavend/system_reply_test.go

@@ -35,6 +35,27 @@ func TestReplySystemDateOffset(t *testing.T) {
 	}
 }
 
+// A day she cannot work out must not come back as today's date — that is the
+// same silent wrong answer #388 was about, one step further out.
+func TestReplySystemUnknownDayIsHonest(t *testing.T) {
+	now := time.Date(2026, 7, 30, 14, 5, 0, 0, time.UTC)
+	h := systemHandler(now)
+	for _, u := range []string{
+		"какое число в пятницу",
+		"какое число через неделю",
+		"какое число в понедельник",
+	} {
+		got := h.replySystem(context.Background(), router.Decision{Utterance: u})
+		if got != onlyNearDaysReply {
+			t.Errorf("replySystem(%q) = %q, want the honest reply", u, got)
+		}
+	}
+	// The days she does know must not be caught by the same guard.
+	if got := h.replySystem(context.Background(), router.Decision{Utterance: "какое число завтра"}); got == onlyNearDaysReply {
+		t.Error("завтра was treated as an unknown day")
+	}
+}
+
 // TestReplySystemClockCity — the clock arm must not answer local time for a
 // question about another city (Vikunja #388). Known cities get their own zone;
 // unknown places get an honest "local time only".

cmd/mavend/voice.go

@@ -755,7 +755,9 @@ func (h *reactiveHandler) applyAction(ctx context.Context, dec router.Decision)
 		}
 
 		// Calendar questions: "что у меня сегодня?", "планы на завтра?"
-		if date, ok := router.ParseCalendarDate(dec.Utterance, time.Now()); ok {
+		// h.now(), not time.Now(): the handler's clock is the injected one, so
+		// this arm can be tested at a fixed time like the rest.
+		if date, ok := router.ParseCalendarDate(dec.Utterance, h.now()); ok {
 			events, err := h.api.CalendarEvents(ctx, date, date.Add(24*time.Hour))
 			if err != nil {
 				log.Printf("voice: calendar events: %v", err)
@@ -1021,6 +1023,33 @@ func mentionsUnknownPlace(u string) bool {
 	return false
 }
 
+// onlyNearDaysReply — she can work out today, tomorrow, the day after and
+// yesterday, and nothing further. Said out loud instead of answering today's
+// date for a day she did not understand.
+const onlyNearDaysReply = "я считаю только сегодня, завтра, послезавтра и вчера — про другие дни пока не скажу."
+
+// dayWords — day references the calendar parser cannot resolve. A weekday name
+// or a "через …" phrase means he asked about a specific other day.
+var dayWords = []string{
+	"понедельник", "вторник", "сред", "четверг", "пятниц", "суббот", "воскресен",
+	"через", "monday", "tuesday", "wednesday", "thursday", "friday", "saturday", "sunday",
+}
+
+// mentionsUnknownDay reports whether the question names a day the calendar
+// parser could not resolve. Mirror of mentionsUnknownPlace: it exists only to
+// pick an honest reply over a confidently wrong one.
+//
+// Only called after ParseCalendarDate has already failed, so "завтра" and the
+// other words it does know never reach here.
+func mentionsUnknownDay(u string) bool {
+	for _, w := range dayWords {
+		if strings.Contains(u, w) {
+			return true
+		}
+	}
+	return false
+}
+
 // ruClock renders the clock part of the time reply: "15 часов 4 минуты".
 func ruClock(t time.Time) string {
 	h, m := t.Hour(), t.Minute()
@@ -1148,6 +1177,11 @@ func (h *reactiveHandler) replySystem(ctx context.Context, dec router.Decision)
 		if d, ok := router.ParseCalendarDate(u, now); ok {
 			day = d
 			prefix = dayPrefix(now, d)
+		} else if mentionsUnknownDay(u) {
+			// He named a day she cannot work out ("в пятницу", "через неделю").
+			// Answering today's date here would be the same silent wrong answer
+			// this arm was fixed for, so say what she can do instead.
+			return onlyNearDaysReply
 		}
 		dow := ruWeekdays[day.Weekday()]
 		month := ruMonths[day.Month()-1]