更新

app/tests/test_widgets_format.py

@@ -46,6 +46,15 @@ def test_format_record_time_with_datetime_returns_minute_precision() -> None:
     assert format_record_time(date(2026, 8, 20)) == "2026-08-20"
 
 
+def test_format_record_time_with_unset_epoch_returns_default() -> None:
+    # The API sends 0 (and occasionally "0") for a snapshot cutoff or finish time that does
+    # not exist yet; it must not be rendered as a bare 0 or as 1970.
+    assert format_record_time(0) == "—"
+    assert format_record_time("0") == "—"
+    assert format_record_time(-1) == "—"
+    assert format_record_time(0, default="未开始") == "未开始"
+
+
 def test_format_record_time_with_garbage_returns_raw_value() -> None:
     assert format_record_time("not-a-timestamp") == "not-a-timestamp"