diff --git a/frontend/src/lib/birth-time-journey-adapters.ts b/frontend/src/lib/birth-time-journey-adapters.ts
index 9697ef09..b7ae47fb 100644
--- a/frontend/src/lib/birth-time-journey-adapters.ts
+++ b/frontend/src/lib/birth-time-journey-adapters.ts
@@ -13,7 +13,7 @@ import type {
 } from "./birth-time-journey-service.ts";
 
 const profileSchema = z.object({
-  birth_date: z.string(),
+  birth_date: z.union([z.string(), z.date().transform((value) => value.toISOString().slice(0, 10))]),
   reported_birth_time: z.string().nullable().optional(),
   birth_time_source: z.enum([
     "hospital_record",
diff --git a/frontend/tests/birth-time-journey-adapters.test.ts b/frontend/tests/birth-time-journey-adapters.test.ts
index ad16a7fb..f25e0194 100644
--- a/frontend/tests/birth-time-journey-adapters.test.ts
+++ b/frontend/tests/birth-time-journey-adapters.test.ts
@@ -30,6 +30,19 @@ test("birth time profile adapter parses an exact hospital declaration", () => {
   }
 });
 
+test("birth time profile adapter normalizes PostgreSQL date values", () => {
+  const assessment = parseBirthTimeProfile({
+    birth_date: new Date("1993-04-17T00:00:00.000Z"),
+    reported_birth_time: "08:16:00",
+    birth_time_source: "hospital_record",
+    uncertainty_before_minutes: 2,
+    uncertainty_after_minutes: 2,
+    ...coordinates,
+  });
+
+  assert.equal(assessment.date, "1993-04-17");
+});
+
 test("birth time profile adapter parses a period without inventing a time", () => {
   const assessment = parseBirthTimeProfile({
     birth_date: "1993-04-17",