Fix city-local nearby station time labels

frontend/hooks/useLeafletMap.ts

@@ -216,6 +216,8 @@ function buildNearbyIconHtml(detail: CityDetail, station: NearbyStation) {
   const utcOffsetSeconds = getDetailUtcOffsetSeconds(detail);
   const formatObsTime = () => {
     const raw = String(station.obs_time || "").trim();
+    const label = String(station.obs_time_label || "").trim();
+    if (station.obs_time_display_tz === "city_local" && label) return label.replace(/Z$/i, "");
     const epochRaw = Number(station.obs_time_epoch);
     const epochMs = Number.isFinite(epochRaw)
       ? epochRaw > 1_000_000_000_000
@@ -226,7 +228,6 @@ function buildNearbyIconHtml(detail: CityDetail, station: NearbyStation) {
       const localOffsetSeconds = utcOffsetSeconds;
       return formatCityLocalDateTime(epochMs, localOffsetSeconds, detail.local_date, isEnglishUi);
     }
-    const label = String(station.obs_time_label || "").trim();
     if (label) return label.replace(/Z$/i, "");
     if (!raw) return "";
     if (raw.endsWith("Z") || raw.includes("+00:00")) {

frontend/lib/dashboard-types.ts

@@ -121,6 +121,7 @@ export interface NearbyStation {
   obs_time?: string | null;
   obs_time_epoch?: number | string | null;
   obs_time_label?: string | null;
+  obs_time_display_tz?: "city_local" | string | null;
   age_minutes?: number | null;
   time_delta_vs_anchor_minutes?: number | null;
   sync_status?: "synced" | "near_realtime" | "lagged" | "stale" | "unknown" | string | null;

src/data_collection/country_networks.py

@@ -76,9 +76,10 @@ def _format_obs_time_label(
     value: Any,
     epoch_value: Any = None,
     display_utc_offset_seconds: Any = None,
+    source_utc_offset_seconds: Any = None,
 ) -> Optional[str]:
     text = str(value or "").strip()
-    parsed = _parse_obs_datetime(value, epoch_value)
+    parsed = _parse_obs_datetime(value, epoch_value, source_utc_offset_seconds)
     if parsed is not None:
         if display_utc_offset_seconds is not None and parsed.tzinfo is not None:
             try:
@@ -160,6 +161,7 @@ def _enrich_station_timing(
             row.get("obs_time"),
             row.get("obs_time_epoch"),
             display_utc_offset_seconds,
+            row.get("obs_time_utc_offset_seconds"),
         )
         if display_utc_offset_seconds is not None and enriched_row.get("obs_time_label"):
             enriched_row["obs_time_display_tz"] = "city_local"

tests/test_country_networks.py

@@ -215,6 +215,32 @@ def test_metar_cluster_obs_time_label_uses_dst_aware_city_time():
     assert row["obs_time_label"] == "07:30"
 
 
+def test_metar_cluster_naive_obs_time_is_interpreted_as_utc_before_city_display():
+    raw = {
+        "metar": {
+            "observation_time": "2026-04-19 08:00",
+            "current": {"temp": 4.0},
+        },
+        "mgm_nearby": [
+            {
+                "name": "Moscow/Vnukovo",
+                "icao": "UUWW",
+                "lat": 55.59,
+                "lon": 37.26,
+                "temp": 4.0,
+                "obs_time": "2026-04-19 08:00",
+            }
+        ],
+    }
+
+    snapshot = build_country_network_snapshot("moscow", raw)
+    row = snapshot["official_nearby"][0]
+
+    assert row["source_code"] == "metar_cluster"
+    assert row["obs_time_label"] == "11:00"
+    assert row["obs_time_display_tz"] == "city_local"
+
+
 def test_china_provider_prefers_nmc_rows_when_available():
     raw = {
         "metar": {