diff --git a/plugins/reporting-governance/package-lock.json b/plugins/reporting-governance/package-lock.json
index a4557bf..1b4abbd 100644
--- a/plugins/reporting-governance/package-lock.json
+++ b/plugins/reporting-governance/package-lock.json
@@ -8,8 +8,9 @@
       "name": "@openclaw/plugin-reporting-governance",
       "version": "0.1.0-mainline",
       "dependencies": {
-        "ajv": "^8.20.0",
-        "yaml": "^2.8.4"
+        "ajv": "^8.17.1",
+        "ajv-formats": "^3.0.1",
+        "yaml": "^2.8.0"
       }
     },
     "node_modules/ajv": {
@@ -28,6 +29,23 @@
         "url": "https://github.com/sponsors/epoberezkin"
       }
     },
+    "node_modules/ajv-formats": {
+      "version": "3.0.1",
+      "resolved": "https://registry.npmjs.org/ajv-formats/-/ajv-formats-3.0.1.tgz",
+      "integrity": "sha512-8iUql50EUR+uUcdRQ3HDqa6EVyo3docL8g5WJ3FNcWmu62IbkGUue/pEyLBW8VGKKucTPgqeks4fIU1DA4yowQ==",
+      "license": "MIT",
+      "dependencies": {
+        "ajv": "^8.0.0"
+      },
+      "peerDependencies": {
+        "ajv": "^8.0.0"
+      },
+      "peerDependenciesMeta": {
+        "ajv": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/fast-deep-equal": {
       "version": "3.1.3",
       "resolved": "https://registry.npmjs.org/fast-deep-equal/-/fast-deep-equal-3.1.3.tgz",
diff --git a/plugins/reporting-governance/package.json b/plugins/reporting-governance/package.json
index 99b9592..e9c8a94 100644
--- a/plugins/reporting-governance/package.json
+++ b/plugins/reporting-governance/package.json
@@ -17,6 +17,7 @@
   },
   "dependencies": {
     "ajv": "^8.17.1",
+    "ajv-formats": "^3.0.1",
     "yaml": "^2.8.0"
   }
 }
diff --git a/plugins/reporting-governance/src/storage/decision-artifact.mjs b/plugins/reporting-governance/src/storage/decision-artifact.mjs
index 6a85d55..05e7f8f 100644
--- a/plugins/reporting-governance/src/storage/decision-artifact.mjs
+++ b/plugins/reporting-governance/src/storage/decision-artifact.mjs
@@ -3,6 +3,7 @@ import fs from 'node:fs';
 import path from 'node:path';
 
 import Ajv2020 from 'ajv/dist/2020.js';
+import addFormats from 'ajv-formats';
 
 const EXPECTED_KIND = 'DecisionRecordArtifact';
 const EXPECTED_API_VERSION = 'reporting-governance/v1alpha1';
@@ -24,6 +25,7 @@ const decisionSchemaPath = path.resolve(repoRoot, 'schemas', 'reporting-governan
 const decisionRecordArtifactSchemaPath = path.resolve(repoRoot, 'schemas', 'reporting-governance', 'decision-record-artifact.schema.json');
 
 const ajv = new Ajv2020({ allErrors: true, strict: false });
+addFormats(ajv);
 const decisionSchema = JSON.parse(fs.readFileSync(decisionSchemaPath, 'utf8'));
 const decisionRecordArtifactSchema = JSON.parse(fs.readFileSync(decisionRecordArtifactSchemaPath, 'utf8'));
 ajv.addSchema(decisionSchema);
diff --git a/plugins/reporting-governance/test/decision-store-runtime.integration.test.mjs b/plugins/reporting-governance/test/decision-store-runtime.integration.test.mjs
index be8d9a9..c7ba4b7 100644
--- a/plugins/reporting-governance/test/decision-store-runtime.integration.test.mjs
+++ b/plugins/reporting-governance/test/decision-store-runtime.integration.test.mjs
@@ -257,3 +257,57 @@ test('persisted decision artifact is consumable by downstream validator without
     fs.rmSync(root, { recursive: true, force: true });
   }
 });
+
+
+test('downstream validator rejects persisted decision artifact with invalid canonical decision datetime format', () => {
+  const root = createFixtureRoot();
+  try {
+    mkdirs(root, ['evidence', 'events', 'queue', 'spool', 'receipts', 'repo']);
+    const statePath = writeState(root);
+    const fakeRepoRoot = path.join(root, 'repo');
+    const decisionsDir = path.join(fakeRepoRoot, 'state', 'decisions');
+    fs.mkdirSync(decisionsDir, { recursive: true });
+
+    const result = executeRuntimeIntegratedGovernance({
+      ...createBaseArgs(),
+      runtime: {
+        state: statePath,
+        evidenceDir: path.join(root, 'evidence'),
+        eventDir: path.join(root, 'events'),
+        queueDir: path.join(root, 'queue'),
+        spoolDir: path.join(root, 'spool'),
+        receiptDir: path.join(root, 'receipts'),
+        senderCommand: `node -e "process.stdout.write(JSON.stringify({state:'sent'}))"`,
+        writeState: true,
+        now: '2026-05-07T08:20:00.000Z',
+      },
+    });
+
+    const queueItem = readSingleJson(path.join(root, 'queue'));
+    const runtimeEventRef = queueItem.evidence_refs.find((ref) => ref.label === 'watchdog_event');
+    const store = createFileDecisionStore({ decisionsDir, repoRootOverride: fakeRepoRoot });
+    const written = store.write({
+      decision: result.planning.decision,
+      receipt: result.planning.receipt,
+      recordedAt: '2026-05-08T04:00:00.000Z',
+      source: {
+        task_id: queueItem.governance.task_id,
+        correlation_id: queueItem.governance.correlation_id,
+        event_id: runtimeEventRef.path,
+      },
+    });
+
+    const persisted = JSON.parse(fs.readFileSync(written.artifactPath, 'utf8'));
+    persisted.spec.decision.operator_notice.deadline = 'tomorrow-ish';
+    fs.writeFileSync(written.artifactPath, `${JSON.stringify(persisted, null, 2)}
+`, 'utf8');
+
+    const malformedPersisted = JSON.parse(fs.readFileSync(written.artifactPath, 'utf8'));
+    assert.throws(
+      () => validateDecisionRecordArtifact(malformedPersisted),
+      /spec\/decision\/operator_notice\/deadline must match format "date-time"/
+    );
+  } finally {
+    fs.rmSync(root, { recursive: true, force: true });
+  }
+});