diff --git a/src/app/(protected)/workorders/_components/detail/use-work-order-slide-over.ts b/src/app/(protected)/workorders/_components/detail/use-work-order-slide-over.ts
index 62a31d71..9120bb5f 100644
--- a/src/app/(protected)/workorders/_components/detail/use-work-order-slide-over.ts
+++ b/src/app/(protected)/workorders/_components/detail/use-work-order-slide-over.ts
@@ -14,6 +14,7 @@ import {
   useUploadWorkOrderMedia,
 } from "@/domain/work-orders/use-cases/use-work-order-mutations";
 import { isWorkOrderDocumentsReadOnly } from "@/domain/work-orders/utils/work-order-media-limits";
+import { todayIso } from "@/domain/work-orders/utils/wizard-date-utils";
 import { useAuthContext } from "@/providers/auth-context";
 import { useSlideOverEditState } from "./use-slide-over-edit-state";
 import { useSlideOverMediaState } from "./use-slide-over-media-state";
@@ -103,7 +104,7 @@ export function useWorkOrderSlideOver({
           // Mirror CompDoc finalize: ensure completedDate then mark docStatus Yes.
           const patch: WorkOrderTablePatch = { docStatus: "Yes" };
           if (!infoSource.completedDate) {
-            patch.completedDate = new Date().toISOString().slice(0, 10);
+            patch.completedDate = todayIso();
           }
           try {
             await new Promise<void>((resolve, reject) => {
diff --git a/src/test/domain/work-orders/utils/wizard-date-utils.test.ts b/src/test/domain/work-orders/utils/wizard-date-utils.test.ts
index 3ee9c66a..8f63bbbf 100644
--- a/src/test/domain/work-orders/utils/wizard-date-utils.test.ts
+++ b/src/test/domain/work-orders/utils/wizard-date-utils.test.ts
@@ -1,8 +1,10 @@
-import { describe, expect, it } from "vitest";
+import { afterEach, describe, expect, it, vi } from "vitest";
 import {
   fmtDateRange,
   fmtShortDate,
+  pad2,
   rangeDayCount,
+  todayIso,
 } from "@/domain/work-orders/utils/wizard-date-utils";
 
 describe("fmtShortDate", () => {
@@ -29,3 +31,27 @@ describe("rangeDayCount", () => {
     expect(rangeDayCount("2026-06-08", "2026-06-08")).toBe(1);
   });
 });
+
+describe("todayIso", () => {
+  afterEach(() => {
+    vi.useRealTimers();
+  });
+
+  it("uses local calendar day, not UTC ISO date, near midnight", () => {
+    // 02:30 UTC is still the previous local evening in Americas (UTC−N).
+    vi.useFakeTimers();
+    vi.setSystemTime(new Date("2026-08-11T02:30:00.000Z"));
+
+    const now = new Date();
+    const expectedLocal = `${now.getFullYear()}-${pad2(now.getMonth() + 1)}-${pad2(now.getDate())}`;
+    const utcSlice = now.toISOString().slice(0, 10);
+
+    expect(todayIso()).toBe(expectedLocal);
+    expect(utcSlice).toBe("2026-08-11");
+
+    if (now.getTimezoneOffset() > 0) {
+      expect(todayIso()).toBe("2026-08-10");
+      expect(todayIso()).not.toBe(utcSlice);
+    }
+  });
+});