diff --git a/services/api/scripts/seed-local.mjs b/services/api/scripts/seed-local.mjs
index 066a774a..71d803ee 100644
--- a/services/api/scripts/seed-local.mjs
+++ b/services/api/scripts/seed-local.mjs
@@ -235,6 +235,27 @@ function minutesAfter(minutes) {
   return new Date(NOW.getTime() + minutes * 60 * 1000);
 }
 
+// IAM-026/BUA-024: keep the synthetic customer-growth story bounded to the
+// June-August 2026 pilot window. July carries the majority of registrations,
+// while only four customer identities land after August 14.
+function platformAnalyticsRegistrationDate(index) {
+  let monthIndex;
+  let day;
+  if (index < 8) {
+    monthIndex = 5;
+    day = 2 + index * 4;
+  } else if (index < 47) {
+    monthIndex = 6;
+    day = 1 + Math.floor(((index - 8) * 31) / 39);
+  } else {
+    monthIndex = 7;
+    const augustIndex = index - 47;
+    day = augustIndex < 12 ? augustIndex + 1 : 15 + (augustIndex - 12) * 2;
+  }
+
+  return new Date(Date.UTC(2026, monthIndex, day, 8 + (index % 9), (index * 11) % 60));
+}
+
 export function buildPlatformAnalyticsRows() {
   const organizationNames = [
     'An Phú Retail',
@@ -268,7 +289,7 @@ export function buildPlatformAnalyticsRows() {
     updatedAt: minutesBefore((3 + index * 7) * 1_440),
   }));
   const users = LOCAL_PLATFORM_ANALYTICS_IDENTITIES.map(([email, displayName], index) => {
-    const daysAgo = 4 + index * 4;
+    const createdAt = platformAnalyticsRegistrationDate(index);
     return {
       id: ids(8_100 + index),
       email,
@@ -277,8 +298,8 @@ export function buildPlatformAnalyticsRows() {
       status: 'ACTIVE',
       securityEpoch: 1,
       mfaReenrollmentRequired: false,
-      createdAt: minutesBefore(daysAgo * 1_440),
-      updatedAt: minutesBefore(Math.max(1, daysAgo - 1) * 1_440),
+      createdAt,
+      updatedAt: new Date(createdAt.getTime() + 6 * 60 * 60 * 1000),
       organizationId: organizations[index % organizations.length].id,
     };
   });
diff --git a/services/api/test/seed-local.test.mjs b/services/api/test/seed-local.test.mjs
index 04d17ae3..67c6dd53 100644
--- a/services/api/test/seed-local.test.mjs
+++ b/services/api/test/seed-local.test.mjs
@@ -217,6 +217,27 @@ test('[IAM-026][BUA-024] platform overview seed uses 63 valid, unique supplied c
   assert.equal(new Set(analytics.users.map((user) => user.email)).size, 63);
 });
 
+test('[IAM-026][BUA-024] platform overview registrations start in June, peak in July, and leave only four customers after August 14', () => {
+  const { users } = buildPlatformAnalyticsRows();
+  const registrationsByMonth = Object.fromEntries(
+    ['2026-06', '2026-07', '2026-08'].map((month) => [
+      month,
+      users.filter((user) => user.createdAt.toISOString().startsWith(month)).length,
+    ]),
+  );
+
+  assert.deepEqual(registrationsByMonth, {
+    '2026-06': 8,
+    '2026-07': 39,
+    '2026-08': 16,
+  });
+  assert.ok(users.every((user) => user.createdAt >= new Date('2026-06-01T00:00:00.000Z')));
+  assert.equal(
+    users.filter((user) => user.createdAt >= new Date('2026-08-15T00:00:00.000Z')).length,
+    4,
+  );
+});
+
 test('[IAM-026][BUA-024] platform overview seed models 21 distinct paid actors at 3,129,000 VND', () => {
   const analytics = buildPlatformAnalyticsRows();
   const paidOrders = analytics.paymentOrders.filter((order) => order.status === 'PAID');