diff --git a/docs/hosted-managed-operations.md b/docs/hosted-managed-operations.md
index 11019bb..b4b3579 100644
--- a/docs/hosted-managed-operations.md
+++ b/docs/hosted-managed-operations.md
@@ -433,7 +433,7 @@ Run the isolated maintenance profile explicitly; it is not started by normal
 `up`:
 
 ```bash
-backup_id="production-$(date -u +%Y%m%dT%H%M%SZ)"
+backup_id="production-$(date -u +%Y%m%dt%H%M%Sz)"
 docker compose --project-name platform-managed-production \
   --file docker-compose.hosted-managed-production.example.yml \
   --profile maintenance run --rm managed-operation-maintenance \
diff --git a/tests/test_hosted_managed_production.py b/tests/test_hosted_managed_production.py
index 93e0ee5..6a213ce 100644
--- a/tests/test_hosted_managed_production.py
+++ b/tests/test_hosted_managed_production.py
@@ -116,6 +116,20 @@ def test_dry_run_requires_explicit_preflight_mode(self) -> None:
 
 
 class HostedManagedRuntimeBackupTests(unittest.TestCase):
+    def test_runbook_backup_id_matches_runtime_contract(self) -> None:
+        runbook = (
+            Path(__file__).resolve().parents[1]
+            / "docs"
+            / "hosted-managed-operations.md"
+        ).read_text(encoding="utf-8")
+        self.assertIn(
+            'backup_id="production-$(date -u +%Y%m%dt%H%M%Sz)"',
+            runbook,
+        )
+        self.assertIsNotNone(
+            backup.BACKUP_ID_PATTERN.fullmatch("production-20260713t002228z")
+        )
+
     def test_backup_archives_workspace_artifacts_without_paths_in_summary(self) -> None:
         with tempfile.TemporaryDirectory() as temp_dir:
             root = Path(temp_dir)