diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1f81deb5d..d7ef0ce74 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,15 @@
 
 ## [Unreleased]
 
+### Fixed
+
+- Marking an older missed dose as taken from the intake history now records
+  the dose at the slot's own date and time. Marking Tuesday 09:00 from a
+  Thursday evening used to land on the right slot but stamp the intake with
+  the current moment; the recorded time now matches the claim being made. The
+  optimistic paint had promised this all along, and the skipped-to-taken flip
+  in the same view already behaved this way.
+
 ## [1.37.1] — 2026-08-08
 
 ### Added
diff --git a/public/sw.js b/public/sw.js
index d2632934b..d62c81e76 100644
--- a/public/sw.js
+++ b/public/sw.js
@@ -36,7 +36,7 @@ try {
 // v1.4.38.4 → v1.4.42. Do not hand-edit; bump `package.json` and rebuild.
 const CACHE_VERSION =
   (typeof self !== "undefined" && self.__APP_VERSION__) ||
-  /* @sw-version-fallback */ "v1.37.0";
+  /* @sw-version-fallback */ "v1.37.1";
 const STATIC_CACHE = `healthlog-static-${CACHE_VERSION}`;
 const PAGE_CACHE = `healthlog-pages-${CACHE_VERSION}`;
 // v1.18.6 — read-only data cache for a curated allowlist of safe GET `/api/*`
diff --git a/src/components/medications/__tests__/dose-history-ledger-compute.test.ts b/src/components/medications/__tests__/dose-history-ledger-compute.test.ts
index 420d73a1b..496be10f6 100644
--- a/src/components/medications/__tests__/dose-history-ledger-compute.test.ts
+++ b/src/components/medications/__tests__/dose-history-ledger-compute.test.ts
@@ -2,6 +2,7 @@ import { describe, expect, it } from "vitest";
 
 import {
   applyOptimisticSlotMark,
+  slotMarkRequestBody,
   complianceFromLedger,
   formatSlotDelta,
   groupLedgerByDay,
@@ -195,3 +196,23 @@ describe("applyOptimisticSlotMark", () => {
     expect(next.rows[0].status).toBe("taken_late");
   });
 });
+
+describe("slotMarkRequestBody", () => {
+  const row = { at: "2026-08-04T07:00:00.000Z" };
+
+  it("anchors takenAt on the slot instant, not on now", () => {
+    const body = slotMarkRequestBody(row, "taken");
+    expect(body).toEqual({
+      skipped: false,
+      scheduledFor: "2026-08-04T07:00:00.000Z",
+      takenAt: "2026-08-04T07:00:00.000Z",
+    });
+  });
+
+  it("keeps the skipped arm free of takenAt", () => {
+    expect(slotMarkRequestBody(row, "skipped")).toEqual({
+      skipped: true,
+      scheduledFor: "2026-08-04T07:00:00.000Z",
+    });
+  });
+});
diff --git a/src/components/medications/dose-history-ledger-compute.ts b/src/components/medications/dose-history-ledger-compute.ts
index 06f51e084..9bb009e35 100644
--- a/src/components/medications/dose-history-ledger-compute.ts
+++ b/src/components/medications/dose-history-ledger-compute.ts
@@ -204,3 +204,18 @@ export function applyOptimisticSlotMark(
   });
   return { ...payload, rows };
 }
+
+/**
+ * Request body for marking a ledger slot from the Verlauf. The taken arm
+ * anchors `takenAt` on the slot instant: marking Tuesday 09:00 from a
+ * Thursday evening records a dose taken Tuesday 09:00, which is the claim
+ * the person is making. The optimistic paint above already promised this.
+ */
+export function slotMarkRequestBody(
+  row: Pick<LedgerRow, "at">,
+  action: "taken" | "skipped",
+): Record<string, unknown> {
+  return action === "skipped"
+    ? { skipped: true, scheduledFor: row.at }
+    : { skipped: false, scheduledFor: row.at, takenAt: row.at };
+}
diff --git a/src/components/medications/dose-history-ledger.tsx b/src/components/medications/dose-history-ledger.tsx
index 9204ed83d..82b6ae50e 100644
--- a/src/components/medications/dose-history-ledger.tsx
+++ b/src/components/medications/dose-history-ledger.tsx
@@ -106,6 +106,7 @@ import {
   formatSlotDelta,
   groupLedgerByDay,
   isSlotActionable,
+  slotMarkRequestBody,
   type LedgerPayload,
   type LedgerRow,
 } from "@/components/medications/dose-history-ledger-compute";
@@ -273,18 +274,13 @@ export function DoseHistoryLedger({
 
       try {
         // Pin the displayed slot so the server marks THAT dose (the canonical
-        // slot upsert), not a now-snap to the nearest one. The POST returns
-        // the created event; its id drives the Undo affordance (the same
-        // soft-delete route the cards use).
+        // slot upsert), not a now-snap to the nearest one — and anchor
+        // `takenAt` on the same instant, matching the optimistic paint. The
+        // POST returns the created event; its id drives the Undo affordance
+        // (the same soft-delete route the cards use).
         const created = await apiPost<{ id?: string } | undefined>(
           `/api/medications/${medicationId}/intake`,
-          action === "skipped"
-            ? { skipped: true, scheduledFor: row.at }
-            : {
-                skipped: false,
-                scheduledFor: row.at,
-                takenAt: new Date().toISOString(),
-              },
+          slotMarkRequestBody(row, action),
         );
         const eventId: string | undefined = created?.id;
         toast.success(