diff --git a/AGENTS.md b/AGENTS.md
index 87c46c9..2616f78 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -32,4 +32,4 @@ This is a personal agenda web application built with Flask that tracks various e
 - Personal data directory (`personal-data/`) is excluded from git
 
 ## Notes
-- Trip stats new-country badges come from `agenda.stats.calculate_yearly_stats` via `year_stats.new_countries` (first-visit year, excluding `PREVIOUSLY_VISITED`).
+- Trip stats new-country badges come from `agenda.stats.calculate_yearly_stats` via `year_stats.new_countries` (first-visit year); `templates/trip/stats.html` filters against `PREVIOUSLY_VISITED`.
diff --git a/agenda/busy.py b/agenda/busy.py
index 582bbce..8452903 100644
--- a/agenda/busy.py
+++ b/agenda/busy.py
@@ -81,16 +81,15 @@ def get_busy_events(
     return busy_events
 
 
-def _parse_datetime_field(datetime_obj: datetime | date | str) -> tuple[datetime, date]:
+def _parse_datetime_field(datetime_obj: datetime | date) -> tuple[datetime, date]:
     """Parse a datetime field that could be datetime object or string."""
-    if isinstance(datetime_obj, datetime):
+    if hasattr(datetime_obj, "date"):
         return datetime_obj, datetime_obj.date()
-    if isinstance(datetime_obj, date):
-        return datetime.combine(datetime_obj, datetime.min.time()), datetime_obj
-    if isinstance(datetime_obj, str):
+    elif isinstance(datetime_obj, str):
         dt = datetime.fromisoformat(datetime_obj.replace("Z", "+00:00"))
         return dt, dt.date()
-    raise ValueError(f"Invalid datetime format: {datetime_obj}")
+    else:
+        raise ValueError(f"Invalid datetime format: {datetime_obj}")
 
 
 def _get_accommodation_location(
@@ -106,15 +105,13 @@ def _get_accommodation_location(
 def _find_most_recent_travel_within_trip(
     trip: Trip,
     target_date: date,
-) -> tuple[str | None, pycountry.db.Country | None] | None:
+) -> tuple[str | None, pycountry.db.Country] | None:
     """Find the most recent travel location within a trip."""
     uk_airports = {"LHR", "LGW", "STN", "LTN", "BRS", "BHX", "MAN", "EDI", "GLA"}
 
-    trip_most_recent_date: date | None = None
-    trip_most_recent_location: tuple[str | None, pycountry.db.Country | None] | None = (
-        None
-    )
-    trip_most_recent_datetime: datetime | None = None
+    trip_most_recent_date = None
+    trip_most_recent_location = None
+    trip_most_recent_datetime = None
 
     # Check flights within trip period
     for travel_item in trip.travel:
@@ -289,9 +286,6 @@ def _get_trip_location_by_progression(
         return (city, country)
 
     # Multiple locations: use progression through the trip
-    if not trip.end:
-        city, country = locations[-1]
-        return (city, country)
     trip_duration = (trip.end - trip.start).days + 1
     days_into_trip = (target_date - trip.start).days
 
@@ -311,9 +305,9 @@ def _find_most_recent_travel_before_date(
     """Find the most recent travel location before a given date."""
     uk_airports = {"LHR", "LGW", "STN", "LTN", "BRS", "BHX", "MAN", "EDI", "GLA"}
 
-    most_recent_location: tuple[str | None, pycountry.db.Country | None] | None = None
-    most_recent_date: date | None = None
-    most_recent_datetime: datetime | None = None
+    most_recent_location = None
+    most_recent_date = None
+    most_recent_datetime = None
 
     # Check all travel across all trips
     for trip in trips:
diff --git a/agenda/calendar.py b/agenda/calendar.py
index 0a66b6c..f037a3c 100644
--- a/agenda/calendar.py
+++ b/agenda/calendar.py
@@ -100,7 +100,7 @@ def build_toastui_events(events: list[Event]) -> list[dict[str, typing.Any]]:
                 end_date = e.as_date
             end_iso = end_date.isoformat()
 
-        item: dict[str, typing.Any] = {
+        item = {
             "id": str(uuid.uuid4()),
             "calendarId": calendar_id,
             "title": e.title_with_emoji,
diff --git a/agenda/stats.py b/agenda/stats.py
index c3c8e4f..c74d94e 100644
--- a/agenda/stats.py
+++ b/agenda/stats.py
@@ -33,13 +33,10 @@ def conferences(trip: Trip, yearly_stats: Mapping[int, StrDict]) -> None:
         yearly_stats[c["start"].year]["conferences"] += 1
 
 
-def calculate_yearly_stats(
-    trips: list[Trip], previously_visited: set[str] | None = None
-) -> dict[int, StrDict]:
+def calculate_yearly_stats(trips: list[Trip]) -> dict[int, StrDict]:
     """Calculate total distance and distance by transport type grouped by year."""
     yearly_stats: defaultdict[int, StrDict] = defaultdict(dict)
     first_visit_year: dict[str, int] = {}
-    excluded_new: set[str] = previously_visited or set()
 
     for trip in trips:
         year = trip.start.year
@@ -75,10 +72,7 @@ def calculate_yearly_stats(
                 continue
             yearly_stats[year].setdefault("countries", set())
             yearly_stats[year]["countries"].add(country)
-            if (
-                first_visit_year.get(country.alpha_2) == year
-                and country.alpha_2 not in excluded_new
-            ):
+            if first_visit_year.get(country.alpha_2) == year:
                 yearly_stats[year].setdefault("new_countries", set())
                 yearly_stats[year]["new_countries"].add(country)
 
diff --git a/agenda/trip.py b/agenda/trip.py
index cb96981..03ebcd1 100644
--- a/agenda/trip.py
+++ b/agenda/trip.py
@@ -25,7 +25,7 @@ class Airline(typing.TypedDict, total=False):
 
 def load_travel(travel_type: str, plural: str, data_dir: str) -> list[StrDict]:
     """Read flight and train journeys."""
-    items: list[StrDict] = travel.parse_yaml(plural, data_dir)
+    items = typing.cast(list[StrDict], travel.parse_yaml(plural, data_dir))
     for item in items:
         item["type"] = travel_type
     return items
diff --git a/templates/trip/stats.html b/templates/trip/stats.html
index e07766d..0e65005 100644
--- a/templates/trip/stats.html
+++ b/templates/trip/stats.html
@@ -27,13 +27,19 @@
     <div>Trips in {{ year }}: {{ year_stats.count }}</div>
     <div>Conferences in {{ year }}: {{ year_stats.conferences }}</div>
     <div>{{ countries | count }} countries visited in {{ year }}:
-      {% if new_countries %}
-        ({{ new_countries | count }} new)
+      {% set display_new_countries = [] %}
+      {% for c in new_countries %}
+        {% if c.alpha_2 not in previously_visited %}
+          {% set _ = display_new_countries.append(c) %}
+        {% endif %}
+      {% endfor %}
+      {% if display_new_countries %}
+        ({{ display_new_countries | count }} new)
       {% endif %}
       {% for c in countries %}
         <span class="d-inline-block border border-2 p-1 m-1">
           {{ c.flag }} {{ c.name }} ({{ c.alpha_2 }})
-          {% if c in new_countries %}
+          {% if c in display_new_countries %}
             <span class="badge text-bg-info">new</span>
           {% endif %}
         </span>
diff --git a/tests/test_trip_stats.py b/tests/test_trip_stats.py
index 37d04b6..20ff7f5 100644
--- a/tests/test_trip_stats.py
+++ b/tests/test_trip_stats.py
@@ -27,11 +27,3 @@ def test_new_country_only_first_year() -> None:
     assert czechia in yearly_stats[2024]["new_countries"]
     assert czechia in yearly_stats[2026]["countries"]
     assert "new_countries" not in yearly_stats[2026]
-
-
-def test_new_country_respects_previously_visited() -> None:
-    """Ensure previously visited countries are excluded from new-country stats."""
-    trips = [make_trip(date(2024, 5, 1), "CZ")]
-
-    yearly_stats = calculate_yearly_stats(trips, {"CZ"})
-    assert "new_countries" not in yearly_stats[2024]
diff --git a/web_view.py b/web_view.py
index a61e257..fa3c8ee 100755
--- a/web_view.py
+++ b/web_view.py
@@ -461,9 +461,7 @@ def accommodation_list() -> str:
     items = travel.parse_yaml("accommodation", data_dir)
 
     # Create a dictionary to hold stats for each year
-    year_stats: defaultdict[int, dict[str, int]] = defaultdict(
-        lambda: {"total_nights": 0, "nights_abroad": 0}
-    )
+    year_stats = defaultdict(lambda: {"total_nights": 0, "nights_abroad": 0})
 
     # Calculate stats for each year
     for stay in items:
@@ -538,7 +536,7 @@ def calc_total_distance(trips: list[Trip]) -> float:
 
 def calc_total_co2_kg(trips: list[Trip]) -> float:
     """Total CO₂ for trips."""
-    return sum(item.total_co2_kg() or 0.0 for item in trips)
+    return sum(item.total_co2_kg() for item in trips)
 
 
 def sum_distances_by_transport_type(trips: list[Trip]) -> list[tuple[str, float]]:
@@ -808,9 +806,7 @@ def trip_stats() -> str:
 
     conferences = sum(len(item.conferences) for item in trip_list)
 
-    yearly_stats = agenda.stats.calculate_yearly_stats(
-        trip_list, app.config.get("PREVIOUSLY_VISITED")
-    )
+    yearly_stats = agenda.stats.calculate_yearly_stats(trip_list)
 
     return flask.render_template(
         "trip/stats.html",