diff --git a/src/lib/jobs/__tests__/medication-reminder-check.test.ts b/src/lib/jobs/__tests__/medication-reminder-check.test.ts
index a47225f06..053d222c3 100644
--- a/src/lib/jobs/__tests__/medication-reminder-check.test.ts
+++ b/src/lib/jobs/__tests__/medication-reminder-check.test.ts
@@ -111,6 +111,7 @@ vi.mock("@/lib/notifications/reminder-dedup", () => ({
 import {
   handleReminderCheck,
   nextSlotHeldBySnooze,
+  slotClock,
 } from "@/lib/jobs/reminder/medication-reminder-check";
 import { dispatchNotification } from "@/lib/notifications/dispatcher";
 import { isModuleEnabled } from "@/lib/modules/gate";
@@ -308,6 +309,54 @@ describe("handleReminderCheck per-slot reminder windows", () => {
   });
 });
 
+describe("the slot time in the reminder text follows the 12/24-hour setting", () => {
+  // 20:00 in Berlin on a summer day.
+  const slot = new Date("2026-07-28T18:00:00.000Z");
+
+  it("AUTO follows the message's language", () => {
+    const clock = slotClock(slot, "Europe/Berlin", {
+      timeFormat: "AUTO",
+      dateFormat: "AUTO",
+    });
+    expect(clock("en")).toBe("08:00 PM");
+    expect(clock("de")).toBe("20:00");
+  });
+
+  it("an explicit choice wins over the language", () => {
+    expect(
+      slotClock(slot, "Europe/Berlin", {
+        timeFormat: "H24",
+        dateFormat: "AUTO",
+      })("en"),
+    ).toBe("20:00");
+    expect(
+      slotClock(slot, "Europe/Berlin", {
+        timeFormat: "H12",
+        dateFormat: "AUTO",
+      })("de"),
+    ).toBe("08:00 PM");
+  });
+
+  it("the dispatched reminder carries the person's clock", async () => {
+    vi.useFakeTimers();
+    vi.setSystemTime(new Date("2026-07-28T09:15:00.000Z"));
+    const medication = medicationWithSchedule({
+      windowEnd: "18:00",
+      timesOfDay: ["08:00", "18:00"],
+    });
+    prismaMock.medication.findMany.mockResolvedValue([medication]);
+
+    await handleReminderCheck([]);
+
+    expect(dispatchNotification).toHaveBeenCalledTimes(1);
+    const payload = vi.mocked(dispatchNotification).mock.calls[0][0];
+    // An `en` owner on AUTO reads a 12-hour clock, as on the medication card.
+    expect(payload.message).toContain("08:00 AM");
+    // A recipient in another language gets that language's clock.
+    expect(payload.renderForRecipient?.("de").message).toContain("08:00)");
+  });
+});
+
 describe("handleReminderCheck medication-wide slot attribution", () => {
   it("lets an overlapping schedule claim the nearest medication-wide slot", async () => {
     vi.useFakeTimers();
diff --git a/src/lib/jobs/reminder/medication-reminder-check.ts b/src/lib/jobs/reminder/medication-reminder-check.ts
index c7fa1dbc4..b57f86942 100644
--- a/src/lib/jobs/reminder/medication-reminder-check.ts
+++ b/src/lib/jobs/reminder/medication-reminder-check.ts
@@ -49,6 +49,11 @@ import { DEFAULT_TIMEZONE } from "@/lib/tz/format";
 import { MEDICATION_SCHEDULE_ORDER } from "@/lib/medications/read-order";
 import { isModuleEnabled } from "@/lib/modules/gate";
 import { getEvent } from "@/lib/logging/context";
+import {
+  makeFormatters,
+  type DateFormatPreference,
+  type TimeFormatPreference,
+} from "@/lib/format-locale";
 
 export interface ReminderCheckPayload {
   triggeredAt: string;
@@ -93,6 +98,9 @@ async function loadRemindableMedications(
           // Used to localise the reminder title / message / keyboard
           // labels per user. Null falls back to the app default.
           locale: true,
+          // How the slot time is spelled (`slotClock`).
+          timeFormat: true,
+          dateFormat: true,
         },
       },
     },
@@ -110,6 +118,27 @@ async function loadRemindableMedications(
   return medications.filter((med) => !moduleOff.has(med.user.id));
 }
 
+/**
+ * The slot's clock time as the person reads it everywhere else in the app:
+ * their hour cycle, through the same formatter as the medication card. AUTO
+ * follows the message's language, so an `en` reminder reads "08:00 PM" where
+ * a `de` one reads "20:00". The slot's instant is formatted in the person's
+ * zone; the bare `HH:mm` would be read in the server's.
+ */
+export function slotClock(
+  slot: Date,
+  timeZone: string,
+  person: {
+    timeFormat: TimeFormatPreference;
+    dateFormat: DateFormatPreference;
+  },
+): (locale: Locale) => string {
+  return (locale) =>
+    makeFormatters(locale, timeZone, person.timeFormat, person.dateFormat).time(
+      slot,
+    );
+}
+
 /**
  * Whether a medication-level snooze holds the reminder of one slot. It
  * holds only while it runs (`now < snoozedUntil`), and only for a slot whose
@@ -613,7 +642,7 @@ export async function handleReminderCheck(
             }
 
             const doseInfo = schedule.dose ?? med.dose;
-            const timeWindow = `${slotTime}`;
+            const timeWindow = slotClock(slotScheduledFor, userTz, med.user);
 
             // RED phase: create missed intake event for this slot.
             if (currentPhase === "RED") {
@@ -663,7 +692,7 @@ export async function handleReminderCheck(
                 currentPhase,
                 med.name,
                 doseInfo,
-                timeWindow,
+                timeWindow(recipientLocale),
                 Math.ceil(minutesToEnd),
                 recipientLocale,
               );
@@ -672,7 +701,7 @@ export async function handleReminderCheck(
                   currentPhase,
                   med.name,
                   doseInfo,
-                  timeWindow,
+                  timeWindow(locale),
                   Math.ceil(minutesToEnd),
                   locale,
                 );