diff --git a/src/app/api/documents/inbound/[id]/__tests__/route.test.ts b/src/app/api/documents/inbound/[id]/__tests__/route.test.ts
index 3b1f74874..b82bd9d65 100644
--- a/src/app/api/documents/inbound/[id]/__tests__/route.test.ts
+++ b/src/app/api/documents/inbound/[id]/__tests__/route.test.ts
@@ -232,6 +232,29 @@ describe("PATCH /api/documents/inbound/[id]", () => {
     expect("documentDate" in arg.data).toBe(false);
   });
 
+  it("stores an edited filing date at noon UTC so it reads back on that day everywhere", async () => {
+    vi.mocked(prisma.inboundDocument.findFirst).mockResolvedValue({
+      id: "doc-1",
+    } as never);
+    vi.mocked(prisma.inboundDocument.update).mockResolvedValue(
+      docRow() as never,
+    );
+    vi.mocked(prisma.inboundDocument.findFirstOrThrow).mockResolvedValue(
+      docRow() as never,
+    );
+
+    const res = await PATCH(
+      mkReq("doc-1", { documentDate: "2026-05-03" }) as never,
+      ctx("doc-1") as never,
+    );
+    expect(res.status).toBe(200);
+    const arg = vi.mocked(prisma.inboundDocument.update).mock.calls[0][0];
+    // UTC midnight is the previous evening west of UTC.
+    expect((arg.data.documentDate as Date).toISOString()).toBe(
+      "2026-05-03T12:00:00.000Z",
+    );
+  });
+
   it("422s on an empty update", async () => {
     const res = await PATCH(mkReq("doc-1", {}) as never, ctx("doc-1") as never);
     expect(res.status).toBe(422);
diff --git a/src/app/api/documents/inbound/[id]/extract/__tests__/route.test.ts b/src/app/api/documents/inbound/[id]/extract/__tests__/route.test.ts
index 267c366bd..ccb39338b 100644
--- a/src/app/api/documents/inbound/[id]/extract/__tests__/route.test.ts
+++ b/src/app/api/documents/inbound/[id]/extract/__tests__/route.test.ts
@@ -288,6 +288,14 @@ describe("POST /api/documents/inbound/[id]/extract — stored mode", () => {
         data: expect.objectContaining({ status: "EXTRACTED" }),
       }),
     );
+    // The stated report date is a date-only value: stored at noon UTC, not
+    // at UTC midnight (the previous evening west of UTC).
+    const staged = tx.inboundDocument.update.mock.calls[0]![0] as {
+      data: { reportDate: Date };
+    };
+    expect(staged.data.reportDate.toISOString()).toBe(
+      "2026-08-01T12:00:00.000Z",
+    );
     expect(auditLog).toHaveBeenCalledWith(
       "documents.inbound.extract",
       expect.objectContaining({
diff --git a/src/app/api/documents/inbound/[id]/extract/route.ts b/src/app/api/documents/inbound/[id]/extract/route.ts
index f6bd96a3b..930d8c895 100644
--- a/src/app/api/documents/inbound/[id]/extract/route.ts
+++ b/src/app/api/documents/inbound/[id]/extract/route.ts
@@ -76,6 +76,7 @@ import {
   inboundStoredExtractSchema,
   inboundTextExtractSchema,
 } from "@/lib/validations/inbound-documents";
+import { dateOnlyAtNoonUtc } from "@/lib/tz/date-only";
 
 export const dynamic = "force-dynamic";
 
@@ -111,7 +112,7 @@ async function stageExtraction(
         status: "EXTRACTED",
         providerType: result.providerType,
         reportDate: result.reportDate
-          ? new Date(`${result.reportDate}T00:00:00.000Z`)
+          ? dateOnlyAtNoonUtc(result.reportDate)
           : null,
         facts: {
           create: result.facts.map((f) => ({
diff --git a/src/app/api/documents/inbound/[id]/route.ts b/src/app/api/documents/inbound/[id]/route.ts
index 8876d279c..b6f512a27 100644
--- a/src/app/api/documents/inbound/[id]/route.ts
+++ b/src/app/api/documents/inbound/[id]/route.ts
@@ -41,6 +41,7 @@ import {
   toContentIndexSource,
 } from "@/lib/validations/inbound-documents";
 import type { Prisma } from "@/generated/prisma/client";
+import { dateOnlyAtNoonUtc } from "@/lib/tz/date-only";
 
 type RouteParams = { params: Promise<{ id: string }> };
 
@@ -232,7 +233,7 @@ export const PATCH = apiHandler(
     if (parsed.data.kind !== undefined) data.kind = parsed.data.kind;
     if (parsed.data.documentDate !== undefined) {
       data.documentDate = parsed.data.documentDate
-        ? new Date(`${parsed.data.documentDate}T00:00:00.000Z`)
+        ? dateOnlyAtNoonUtc(parsed.data.documentDate)
         : null;
     }
 
diff --git a/src/lib/documents/__tests__/auto-stage-labs.test.ts b/src/lib/documents/__tests__/auto-stage-labs.test.ts
index 8f522f927..ebcde0792 100644
--- a/src/lib/documents/__tests__/auto-stage-labs.test.ts
+++ b/src/lib/documents/__tests__/auto-stage-labs.test.ts
@@ -159,6 +159,13 @@ describe("maybeAutoStageLabFacts", () => {
         data: expect.objectContaining({ status: "EXTRACTED" }),
       }),
     );
+    // The stated report date is stored at noon UTC, not UTC midnight.
+    const moved = updateMany.mock.calls[0]![0] as {
+      data: { reportDate: Date };
+    };
+    expect(moved.data.reportDate.toISOString()).toBe(
+      "2026-07-10T12:00:00.000Z",
+    );
     const created = createMany.mock.calls[0]![0] as {
       data: { status: string }[];
     };
diff --git a/src/lib/documents/__tests__/commit.test.ts b/src/lib/documents/__tests__/commit.test.ts
index 1e858b531..4a54f40d9 100644
--- a/src/lib/documents/__tests__/commit.test.ts
+++ b/src/lib/documents/__tests__/commit.test.ts
@@ -28,6 +28,7 @@ import { prisma } from "@/lib/db";
 import { resolveOrMintBiomarker } from "@/lib/labs/biomarker-store";
 import { decryptFactData } from "@/lib/documents/store";
 import type { ExtractedFact } from "@/generated/prisma/client";
+import { userDayKey } from "@/lib/tz/format";
 
 function observationFact(): ExtractedFact {
   return {
@@ -94,5 +95,12 @@ describe("commitApprovedFact — OBSERVATION unit integrity", () => {
     const ref = await commitApprovedFact("user-1", observationFact());
     expect(ref).toEqual({ recordType: "labResult", recordId: "lr-1" });
     expect(prisma.labResult.create).toHaveBeenCalledOnce();
+    // The stated date is stored at noon UTC: it reads back on the stated day
+    // as a UTC label and formatted in a zone west of UTC alike. UTC midnight
+    // showed the reading a day early there.
+    const takenAt = vi.mocked(prisma.labResult.create).mock.calls[0]![0].data
+      .takenAt as Date;
+    expect(takenAt.toISOString()).toBe("2025-01-01T12:00:00.000Z");
+    expect(userDayKey(takenAt, "America/Los_Angeles")).toBe("2025-01-01");
   });
 });
diff --git a/src/lib/documents/auto-stage-labs.ts b/src/lib/documents/auto-stage-labs.ts
index c66b24b13..ef9133ee8 100644
--- a/src/lib/documents/auto-stage-labs.ts
+++ b/src/lib/documents/auto-stage-labs.ts
@@ -48,6 +48,7 @@ import { localisedValues } from "@/lib/i18n/shared-resolve";
 import { BIOMARKER_CATALOG } from "@/lib/labs/biomarker-catalog";
 import { annotate } from "@/lib/logging/context";
 import { isModuleEnabled } from "@/lib/modules/gate";
+import { dateOnlyAtNoonUtc } from "@/lib/tz/date-only";
 
 /**
  * Lab-report signals used to decide whether a transcribed document is worth an
@@ -215,7 +216,7 @@ async function stageFactsIfStored(
         status: "EXTRACTED",
         providerType: result.providerType,
         reportDate: result.reportDate
-          ? new Date(`${result.reportDate}T00:00:00.000Z`)
+          ? dateOnlyAtNoonUtc(result.reportDate)
           : null,
       },
     });
diff --git a/src/lib/documents/commit.ts b/src/lib/documents/commit.ts
index e22f3d349..1bc271dfd 100644
--- a/src/lib/documents/commit.ts
+++ b/src/lib/documents/commit.ts
@@ -39,6 +39,7 @@ import type {
   MedicationStatementFactData,
   ObservationFactData,
 } from "@/lib/validations/inbound-documents";
+import { dateOnlyAtNoonUtc, isDateOnlyKey } from "@/lib/tz/date-only";
 
 /** A per-fact commit failure the caller maps to a per-fact 422 entry. */
 export class FactCommitError extends Error {
@@ -55,11 +56,13 @@ export interface CommittedRecordRef {
   recordId: string;
 }
 
-/** Parse a stated YYYY-MM-DD into a UTC instant, or fall back to now. */
+/**
+ * A stated YYYY-MM-DD as the instant a date-only value is stored at (noon
+ * UTC), or now when the document states none. UTC midnight read back as the
+ * previous day anywhere west of UTC.
+ */
 function statedDateOrNow(date: string | null): Date {
-  if (date && /^\d{4}-\d{2}-\d{2}$/u.test(date)) {
-    return new Date(`${date}T00:00:00.000Z`);
-  }
+  if (date && isDateOnlyKey(date)) return dateOnlyAtNoonUtc(date);
   return new Date();
 }
 
diff --git a/src/lib/documents/ingest.ts b/src/lib/documents/ingest.ts
index 0932ba813..ece28bae6 100644
--- a/src/lib/documents/ingest.ts
+++ b/src/lib/documents/ingest.ts
@@ -58,6 +58,9 @@ import type {
   DocumentSourceSystemValue,
   InboundDocumentKindValue,
 } from "@/lib/validations/inbound-documents";
+import { dateOnlyAtNoonUtc } from "@/lib/tz/date-only";
+import { userDayKey } from "@/lib/tz/format";
+import { resolveUserTimezone } from "@/lib/tz/resolver";
 
 /**
  * The person's own uploads per hour, from the web or the phone, and the
@@ -74,7 +77,12 @@ export function personalUploadBucket(userId: string): string {
   return `documents-upload:${userId}`;
 }
 
-/** Parse a YYYY-MM-DD value into a UTC midnight Date. */
+/**
+ * A YYYY-MM-DD as UTC midnight: the lower bound of that date for a range
+ * filter over stored date-only values (which sit at noon UTC, or at UTC
+ * midnight for rows written before the noon anchor). Not a storage anchor;
+ * a stored date goes through `dateOnlyAtNoonUtc`.
+ */
 export function isoDateToUtc(value: string): Date {
   return new Date(`${value}T00:00:00.000Z`);
 }
@@ -297,9 +305,13 @@ export async function ingestDocument(
           contentCodec: codec,
           contentSha256,
           status: "STORED",
-          documentDate: input.documentDate
-            ? isoDateToUtc(input.documentDate)
-            : new Date(),
+          // The upload day when none is stated is the uploader's own day,
+          // not the UTC one (just after midnight east of UTC that was
+          // yesterday).
+          documentDate: dateOnlyAtNoonUtc(
+            input.documentDate ??
+              userDayKey(new Date(), await resolveUserTimezone(input.userId)),
+          ),
           sourceSystem,
           sourceId,
           sourceInstance,
diff --git a/src/lib/tz/date-only.ts b/src/lib/tz/date-only.ts
new file mode 100644
index 000000000..df98246d9
--- /dev/null
+++ b/src/lib/tz/date-only.ts
@@ -0,0 +1,36 @@
+/**
+ * Date-only values: a calendar date (`YYYY-MM-DD`) with no time of day — a
+ * report's stated date, a document's filing date, a backup's label for a
+ * `@db.Date` column.
+ *
+ * Such a value is stored in a timestamp column as noon UTC. Noon keeps the
+ * date on the same calendar day whether it is read back as a UTC label
+ * ({@link dateOnlyKey}) or formatted in any zone from UTC-11 to UTC+11. The
+ * older anchor, UTC midnight, sits on the previous evening everywhere west
+ * of UTC, which is how a stated report date came to show a day early.
+ *
+ * Rows written at UTC midnight before the switch still read back to the same
+ * key through {@link dateOnlyKey}, so the two anchors coexist without a
+ * migration.
+ */
+
+const DATE_ONLY_RE = /^\d{4}-\d{2}-\d{2}$/u;
+
+/** True for a strict `YYYY-MM-DD` string. */
+export function isDateOnlyKey(value: string): boolean {
+  return DATE_ONLY_RE.test(value);
+}
+
+/** The instant a date-only value is stored as: 12:00 UTC on that date. */
+export function dateOnlyAtNoonUtc(key: string): Date {
+  return new Date(`${key}T12:00:00.000Z`);
+}
+
+/**
+ * The calendar date of a stored date-only value (or of a `@db.Date` column,
+ * which Prisma hands back as UTC midnight). Only for values that ARE dates:
+ * the day an instant fell on for a person is `userDayKey(instant, tz)`.
+ */
+export function dateOnlyKey(value: Date): string {
+  return value.toISOString().slice(0, 10);
+}