diff --git a/messages/de.json b/messages/de.json
index 5ff259402..5bcd1478d 100644
--- a/messages/de.json
+++ b/messages/de.json
@@ -10704,6 +10704,7 @@
       "searchPlaceholder": "Biomarker suchen...",
       "searchLabel": "Biomarker suchen",
       "clearSearch": "Suche leeren",
+      "lastMeasured": "Zuletzt gemessen",
       "statusLabel": "Status",
       "statusAll": "Alle Status",
       "statusAbnormal": "Außerhalb des Bereichs",
diff --git a/messages/en.json b/messages/en.json
index 70e699ad3..24628423e 100644
--- a/messages/en.json
+++ b/messages/en.json
@@ -10704,6 +10704,7 @@
       "searchPlaceholder": "Search biomarkers...",
       "searchLabel": "Search biomarkers",
       "clearSearch": "Clear search",
+      "lastMeasured": "Last measured",
       "statusLabel": "Status",
       "statusAll": "All statuses",
       "statusAbnormal": "Out of range",
diff --git a/messages/es.json b/messages/es.json
index 07c64f9df..b65c1d3e4 100644
--- a/messages/es.json
+++ b/messages/es.json
@@ -10704,6 +10704,7 @@
       "searchPlaceholder": "Buscar biomarcadores...",
       "searchLabel": "Buscar biomarcadores",
       "clearSearch": "Borrar búsqueda",
+      "lastMeasured": "Última medición",
       "statusLabel": "Estado",
       "statusAll": "Todos los estados",
       "statusAbnormal": "Fuera de rango",
diff --git a/messages/fr.json b/messages/fr.json
index f09b5c956..9ec5a942e 100644
--- a/messages/fr.json
+++ b/messages/fr.json
@@ -10704,6 +10704,7 @@
       "searchPlaceholder": "Rechercher des biomarqueurs...",
       "searchLabel": "Rechercher des biomarqueurs",
       "clearSearch": "Effacer la recherche",
+      "lastMeasured": "Dernière mesure",
       "statusLabel": "Statut",
       "statusAll": "Tous les statuts",
       "statusAbnormal": "Hors normes",
diff --git a/messages/it.json b/messages/it.json
index a7eb70824..48c188d7a 100644
--- a/messages/it.json
+++ b/messages/it.json
@@ -10704,6 +10704,7 @@
       "searchPlaceholder": "Cerca biomarcatori...",
       "searchLabel": "Cerca biomarcatori",
       "clearSearch": "Cancella ricerca",
+      "lastMeasured": "Ultima misurazione",
       "statusLabel": "Stato",
       "statusAll": "Tutti gli stati",
       "statusAbnormal": "Fuori intervallo",
diff --git a/messages/ko.json b/messages/ko.json
index 9ba285dc9..05130bc50 100644
--- a/messages/ko.json
+++ b/messages/ko.json
@@ -10704,6 +10704,7 @@
       "searchPlaceholder": "바이오마커 검색...",
       "searchLabel": "바이오마커 검색",
       "clearSearch": "검색어 지우기",
+      "lastMeasured": "마지막 측정",
       "statusLabel": "상태",
       "statusAll": "모든 상태",
       "statusAbnormal": "범위 벗어남",
diff --git a/messages/nl.json b/messages/nl.json
index e87e4ed82..9449729b7 100644
--- a/messages/nl.json
+++ b/messages/nl.json
@@ -10704,6 +10704,7 @@
       "searchPlaceholder": "Biomarkers zoeken...",
       "searchLabel": "Biomarkers zoeken",
       "clearSearch": "Zoekopdracht wissen",
+      "lastMeasured": "Laatst gemeten",
       "statusLabel": "Status",
       "statusAll": "Alle statussen",
       "statusAbnormal": "Buiten bereik",
diff --git a/messages/pl.json b/messages/pl.json
index 66fe659d4..62703709b 100644
--- a/messages/pl.json
+++ b/messages/pl.json
@@ -10704,6 +10704,7 @@
       "searchPlaceholder": "Szukaj biomarkerów...",
       "searchLabel": "Szukaj biomarkerów",
       "clearSearch": "Wyczyść wyszukiwanie",
+      "lastMeasured": "Ostatni pomiar",
       "statusLabel": "Status",
       "statusAll": "Wszystkie statusy",
       "statusAbnormal": "Poza zakresem",
diff --git a/messages/pt-BR.json b/messages/pt-BR.json
index a17714148..0903e6cc4 100644
--- a/messages/pt-BR.json
+++ b/messages/pt-BR.json
@@ -10704,6 +10704,7 @@
       "searchPlaceholder": "Buscar biomarcadores...",
       "searchLabel": "Buscar biomarcadores",
       "clearSearch": "Limpar busca",
+      "lastMeasured": "Última medição",
       "statusLabel": "Status",
       "statusAll": "Todos os status",
       "statusAbnormal": "Fora da faixa",
diff --git a/messages/ru.json b/messages/ru.json
index a92addfec..120f1e54d 100644
--- a/messages/ru.json
+++ b/messages/ru.json
@@ -10704,6 +10704,7 @@
       "searchPlaceholder": "Поиск биомаркеров...",
       "searchLabel": "Поиск биомаркеров",
       "clearSearch": "Очистить поиск",
+      "lastMeasured": "Последнее измерение",
       "statusLabel": "Статус",
       "statusAll": "Все статусы",
       "statusAbnormal": "Вне нормы",
diff --git a/src/components/labs/__tests__/lab-filter-rail.browser.test.tsx b/src/components/labs/__tests__/lab-filter-rail.browser.test.tsx
index a6c8ac217..036399eea 100644
--- a/src/components/labs/__tests__/lab-filter-rail.browser.test.tsx
+++ b/src/components/labs/__tests__/lab-filter-rail.browser.test.tsx
@@ -44,7 +44,7 @@ describe("<LabFilterRail> layout", () => {
     const { screen } = await renderWithApp(<LabFilterRail {...props()} />);
 
     const search = screen.getByRole("searchbox", { name: "Search biomarkers" });
-    const dateRange = screen.getByRole("button", { name: "Date range" });
+    const dateRange = screen.getByRole("button", { name: "Last measured" });
     const searchRect = search.element().getBoundingClientRect();
     const dateRect = dateRange.element().getBoundingClientRect();
 
@@ -75,7 +75,7 @@ describe("<LabFilterRail> layout", () => {
 
     const controls = [
       search.element(),
-      screen.getByRole("button", { name: "Date range" }).element(),
+      screen.getByRole("button", { name: "Last measured" }).element(),
       screen.getByRole("combobox", { name: "Status: Out of range" }).element(),
       screen.getByRole("combobox", { name: "Category" }).element(),
       screen.getByRole("button", { name: "Reset" }).element(),
@@ -108,7 +108,7 @@ describe("<LabFilterRail> layout", () => {
 
     const controls = [
       screen.getByRole("searchbox", { name: "Biomarker suchen" }).element(),
-      screen.getByRole("button", { name: "Zeitraum" }).element(),
+      screen.getByRole("button", { name: "Zuletzt gemessen" }).element(),
       screen
         .getByRole("combobox", {
           name: "Status: Außerhalb des Bereichs",
@@ -130,7 +130,7 @@ describe("<LabFilterRail> layout", () => {
     const { screen } = await renderWithApp(<LabFilterRail {...props()} />);
     const controls = [
       screen.getByRole("searchbox", { name: "Search biomarkers" }).element(),
-      screen.getByRole("button", { name: "Date range" }).element(),
+      screen.getByRole("button", { name: "Last measured" }).element(),
       screen.getByRole("combobox", { name: "Status" }).element(),
       screen.getByRole("combobox", { name: "Category" }).element(),
     ];
diff --git a/src/components/labs/__tests__/lab-filter-rail.test.tsx b/src/components/labs/__tests__/lab-filter-rail.test.tsx
index f55178fec..2cb736080 100644
--- a/src/components/labs/__tests__/lab-filter-rail.test.tsx
+++ b/src/components/labs/__tests__/lab-filter-rail.test.tsx
@@ -43,7 +43,7 @@ describe("<LabFilterRail>", () => {
 
     // The shared rail keeps search and all filter dimensions in one ordered row.
     const searchIdx = html.indexOf('placeholder="Search biomarkers..."');
-    const dateRangeIdx = html.indexOf("Date range");
+    const dateRangeIdx = html.indexOf("Last measured");
     const statusIdx = html.indexOf("Status");
     const categoryIdx = html.indexOf("Category");
 
diff --git a/src/components/labs/lab-filter-rail.tsx b/src/components/labs/lab-filter-rail.tsx
index 03519ed5a..ec74754dd 100644
--- a/src/components/labs/lab-filter-rail.tsx
+++ b/src/components/labs/lab-filter-rail.tsx
@@ -113,7 +113,7 @@ export function LabFilterRail({
         </div>
 
         <FilterBarDateRange
-          label={t("dataList.dateRange")}
+          label={t("labs.filter.lastMeasured")}
           from={filters.fromDay ?? ""}
           to={filters.toDay ?? ""}
           onFromChange={onFromDayChange}
diff --git a/src/components/labs/lab-list-filters.ts b/src/components/labs/lab-list-filters.ts
index 6b921360e..ecb8edfc1 100644
--- a/src/components/labs/lab-list-filters.ts
+++ b/src/components/labs/lab-list-filters.ts
@@ -39,7 +39,12 @@ export interface LabListFilters {
   status?: LabStatusFilter;
   /** Category key (matches category.key) or ALL. */
   category?: string;
-  /** Inclusive day bounds, YYYY-MM-DD for newest reading (latest.takenAt). */
+  /**
+   * "Last measured": inclusive day bounds (`?from` / `?to`, YYYY-MM-DD) on
+   * the marker's newest reading (`latest.takenAt`), in the display zone.
+   * Older readings are not looked at, so a marker measured inside the range
+   * and again after it drops out, which is why the pill reads "Last measured".
+   */
   fromDay?: string;
   toDay?: string;
 }
@@ -179,7 +184,7 @@ export function filterMarkerRows(
       if (markerCategory !== category) return false;
     }
 
-    // 4. Date bounds on latest reading
+    // 4. "Last measured": the newest reading's day, never an older one
     if (fromDay || toDay) {
       const takenDate = dayKeyOf(row.latest.takenAt);
       if (fromDay && takenDate < fromDay) return false;