diff --git a/packages/google-cloud-securitycenter/protos/google/cloud/securitycenter/v1/securitycenter_service.proto b/packages/google-cloud-securitycenter/protos/google/cloud/securitycenter/v1/securitycenter_service.proto
index bcb4e863df6..0687928f3ba 100644
--- a/packages/google-cloud-securitycenter/protos/google/cloud/securitycenter/v1/securitycenter_service.proto
+++ b/packages/google-cloud-securitycenter/protos/google/cloud/securitycenter/v1/securitycenter_service.proto
@@ -282,8 +282,20 @@ message GroupAssetsRequest {
   //
   // The following field and operator combinations are supported:
   // name | '='
-  // update_time | '>', '<', '>=', '<=', '='
-  // create_time | '>', '<', '>=', '<=', '='
+  // update_time | '=', '>', '<', '>=', '<='
+  //
+  //   Usage: This should be milliseconds since epoch or an RFC3339 string.
+  //   Examples:
+  //     "update_time = \"2019-06-10T16:07:18-07:00\""
+  //     "update_time = 1560208038000"
+  //
+  // create_time |  '=', '>', '<', '>=', '<='
+  //
+  //   Usage: This should be milliseconds since epoch or an RFC3339 string.
+  //   Examples:
+  //     "create_time = \"2019-06-10T16:07:18-07:00\""
+  //     "create_time = 1560208038000"
+  //
   // iam_policy.policy_blob | '=', ':'
   // resource_properties | '=', ':', '>', '<', '>=', '<='
   // security_marks | '=', ':'
@@ -416,7 +428,13 @@ message GroupFindingsRequest {
   // state | '=', ':'
   // category | '=', ':'
   // external_uri | '=', ':'
-  // event_time | `>`, `<`, `>=`, `<=`
+  // event_time | `=`, `>`, `<`, `>=`, `<=`
+  //
+  //   Usage: This should be milliseconds since epoch or an RFC3339 string.
+  //   Examples:
+  //     "event_time = \"2019-06-10T16:07:18-07:00\""
+  //     "event_time = 1560208038000"
+  //
   // security_marks | '=', ':'
   // source_properties | '=', ':', `>`, `<`, `>=`, `<=`
   //
@@ -572,7 +590,20 @@ message ListAssetsRequest {
   //
   // The following are the allowed field and operator combinations:
   // name | `=`
-  // update_time | `>`, `<`, `>=`, `<=`
+  // update_time | `=`, `>`, `<`, `>=`, `<=`
+  //
+  //   Usage: This should be milliseconds since epoch or an RFC3339 string.
+  //   Examples:
+  //     "update_time = \"2019-06-10T16:07:18-07:00\""
+  //     "update_time = 1560208038000"
+  //
+  // create_time | `=`, `>`, `<`, `>=`, `<=`
+  //
+  //   Usage: This should be milliseconds since epoch or an RFC3339 string.
+  //   Examples:
+  //     "create_time = \"2019-06-10T16:07:18-07:00\""
+  //     "create_time = 1560208038000"
+  //
   // iam_policy.policy_blob | '=', ':'
   // resource_properties | '=', ':', `>`, `<`, `>=`, `<=`
   // security_marks | '=', ':'
@@ -740,7 +771,13 @@ message ListFindingsRequest {
   // state | '=', ':'
   // category | '=', ':'
   // external_uri | '=', ':'
-  // event_time | `>`, `<`, `>=`, `<=`
+  // event_time | `=`, `>`, `<`, `>=`, `<=`
+  //
+  //   Usage: This should be milliseconds since epoch or an RFC3339 string.
+  //   Examples:
+  //     "event_time = \"2019-06-10T16:07:18-07:00\""
+  //     "event_time = 1560208038000"
+  //
   // security_marks | '=', ':'
   // source_properties | '=', ':', `>`, `<`, `>=`, `<=`
   //
diff --git a/packages/google-cloud-securitycenter/src/v1/doc/google/cloud/securitycenter/v1/doc_securitycenter_service.js b/packages/google-cloud-securitycenter/src/v1/doc/google/cloud/securitycenter/v1/doc_securitycenter_service.js
index 057608cf683..5e52ff07702 100644
--- a/packages/google-cloud-securitycenter/src/v1/doc/google/cloud/securitycenter/v1/doc_securitycenter_service.js
+++ b/packages/google-cloud-securitycenter/src/v1/doc/google/cloud/securitycenter/v1/doc_securitycenter_service.js
@@ -128,8 +128,20 @@ const GetSourceRequest = {
  *
  *   The following field and operator combinations are supported:
  *   name | '='
- *   update_time | '>', '<', '>=', '<=', '='
- *   create_time | '>', '<', '>=', '<=', '='
+ *   update_time | '=', '>', '<', '>=', '<='
+ *
+ *     Usage: This should be milliseconds since epoch or an RFC3339 string.
+ *     Examples:
+ *       "update_time = \"2019-06-10T16:07:18-07:00\""
+ *       "update_time = 1560208038000"
+ *
+ *   create_time |  '=', '>', '<', '>=', '<='
+ *
+ *     Usage: This should be milliseconds since epoch or an RFC3339 string.
+ *     Examples:
+ *       "create_time = \"2019-06-10T16:07:18-07:00\""
+ *       "create_time = 1560208038000"
+ *
  *   iam_policy.policy_blob | '=', ':'
  *   resource_properties | '=', ':', '>', '<', '>=', '<='
  *   security_marks | '=', ':'
@@ -284,7 +296,13 @@ const GroupAssetsResponse = {
  *   state | '=', ':'
  *   category | '=', ':'
  *   external_uri | '=', ':'
- *   event_time | `>`, `<`, `>=`, `<=`
+ *   event_time | `=`, `>`, `<`, `>=`, `<=`
+ *
+ *     Usage: This should be milliseconds since epoch or an RFC3339 string.
+ *     Examples:
+ *       "event_time = \"2019-06-10T16:07:18-07:00\""
+ *       "event_time = 1560208038000"
+ *
  *   security_marks | '=', ':'
  *   source_properties | '=', ':', `>`, `<`, `>=`, `<=`
  *
@@ -488,7 +506,20 @@ const ListSourcesResponse = {
  *
  *   The following are the allowed field and operator combinations:
  *   name | `=`
- *   update_time | `>`, `<`, `>=`, `<=`
+ *   update_time | `=`, `>`, `<`, `>=`, `<=`
+ *
+ *     Usage: This should be milliseconds since epoch or an RFC3339 string.
+ *     Examples:
+ *       "update_time = \"2019-06-10T16:07:18-07:00\""
+ *       "update_time = 1560208038000"
+ *
+ *   create_time | `=`, `>`, `<`, `>=`, `<=`
+ *
+ *     Usage: This should be milliseconds since epoch or an RFC3339 string.
+ *     Examples:
+ *       "create_time = \"2019-06-10T16:07:18-07:00\""
+ *       "create_time = 1560208038000"
+ *
  *   iam_policy.policy_blob | '=', ':'
  *   resource_properties | '=', ':', `>`, `<`, `>=`, `<=`
  *   security_marks | '=', ':'
@@ -706,7 +737,13 @@ const ListAssetsResponse = {
  *   state | '=', ':'
  *   category | '=', ':'
  *   external_uri | '=', ':'
- *   event_time | `>`, `<`, `>=`, `<=`
+ *   event_time | `=`, `>`, `<`, `>=`, `<=`
+ *
+ *     Usage: This should be milliseconds since epoch or an RFC3339 string.
+ *     Examples:
+ *       "event_time = \"2019-06-10T16:07:18-07:00\""
+ *       "event_time = 1560208038000"
+ *
  *   security_marks | '=', ':'
  *   source_properties | '=', ':', `>`, `<`, `>=`, `<=`
  *
diff --git a/packages/google-cloud-securitycenter/src/v1/security_center_client.js b/packages/google-cloud-securitycenter/src/v1/security_center_client.js
index de0a471cba3..6cd47b81644 100644
--- a/packages/google-cloud-securitycenter/src/v1/security_center_client.js
+++ b/packages/google-cloud-securitycenter/src/v1/security_center_client.js
@@ -656,8 +656,20 @@ class SecurityCenterClient {
    *
    *   The following field and operator combinations are supported:
    *   name | '='
-   *   update_time | '>', '<', '>=', '<=', '='
-   *   create_time | '>', '<', '>=', '<=', '='
+   *   update_time | '=', '>', '<', '>=', '<='
+   *
+   *     Usage: This should be milliseconds since epoch or an RFC3339 string.
+   *     Examples:
+   *       "update_time = \"2019-06-10T16:07:18-07:00\""
+   *       "update_time = 1560208038000"
+   *
+   *   create_time |  '=', '>', '<', '>=', '<='
+   *
+   *     Usage: This should be milliseconds since epoch or an RFC3339 string.
+   *     Examples:
+   *       "create_time = \"2019-06-10T16:07:18-07:00\""
+   *       "create_time = 1560208038000"
+   *
    *   iam_policy.policy_blob | '=', ':'
    *   resource_properties | '=', ':', '>', '<', '>=', '<='
    *   security_marks | '=', ':'
@@ -871,8 +883,20 @@ class SecurityCenterClient {
    *
    *   The following field and operator combinations are supported:
    *   name | '='
-   *   update_time | '>', '<', '>=', '<=', '='
-   *   create_time | '>', '<', '>=', '<=', '='
+   *   update_time | '=', '>', '<', '>=', '<='
+   *
+   *     Usage: This should be milliseconds since epoch or an RFC3339 string.
+   *     Examples:
+   *       "update_time = \"2019-06-10T16:07:18-07:00\""
+   *       "update_time = 1560208038000"
+   *
+   *   create_time |  '=', '>', '<', '>=', '<='
+   *
+   *     Usage: This should be milliseconds since epoch or an RFC3339 string.
+   *     Examples:
+   *       "create_time = \"2019-06-10T16:07:18-07:00\""
+   *       "create_time = 1560208038000"
+   *
    *   iam_policy.policy_blob | '=', ':'
    *   resource_properties | '=', ':', '>', '<', '>=', '<='
    *   security_marks | '=', ':'
@@ -1024,7 +1048,13 @@ class SecurityCenterClient {
    *   state | '=', ':'
    *   category | '=', ':'
    *   external_uri | '=', ':'
-   *   event_time | `>`, `<`, `>=`, `<=`
+   *   event_time | `=`, `>`, `<`, `>=`, `<=`
+   *
+   *     Usage: This should be milliseconds since epoch or an RFC3339 string.
+   *     Examples:
+   *       "event_time = \"2019-06-10T16:07:18-07:00\""
+   *       "event_time = 1560208038000"
+   *
    *   security_marks | '=', ':'
    *   source_properties | '=', ':', `>`, `<`, `>=`, `<=`
    *
@@ -1236,7 +1266,13 @@ class SecurityCenterClient {
    *   state | '=', ':'
    *   category | '=', ':'
    *   external_uri | '=', ':'
-   *   event_time | `>`, `<`, `>=`, `<=`
+   *   event_time | `=`, `>`, `<`, `>=`, `<=`
+   *
+   *     Usage: This should be milliseconds since epoch or an RFC3339 string.
+   *     Examples:
+   *       "event_time = \"2019-06-10T16:07:18-07:00\""
+   *       "event_time = 1560208038000"
+   *
    *   security_marks | '=', ':'
    *   source_properties | '=', ':', `>`, `<`, `>=`, `<=`
    *
@@ -1357,7 +1393,20 @@ class SecurityCenterClient {
    *
    *   The following are the allowed field and operator combinations:
    *   name | `=`
-   *   update_time | `>`, `<`, `>=`, `<=`
+   *   update_time | `=`, `>`, `<`, `>=`, `<=`
+   *
+   *     Usage: This should be milliseconds since epoch or an RFC3339 string.
+   *     Examples:
+   *       "update_time = \"2019-06-10T16:07:18-07:00\""
+   *       "update_time = 1560208038000"
+   *
+   *   create_time | `=`, `>`, `<`, `>=`, `<=`
+   *
+   *     Usage: This should be milliseconds since epoch or an RFC3339 string.
+   *     Examples:
+   *       "create_time = \"2019-06-10T16:07:18-07:00\""
+   *       "create_time = 1560208038000"
+   *
    *   iam_policy.policy_blob | '=', ':'
    *   resource_properties | '=', ':', `>`, `<`, `>=`, `<=`
    *   security_marks | '=', ':'
@@ -1570,7 +1619,20 @@ class SecurityCenterClient {
    *
    *   The following are the allowed field and operator combinations:
    *   name | `=`
-   *   update_time | `>`, `<`, `>=`, `<=`
+   *   update_time | `=`, `>`, `<`, `>=`, `<=`
+   *
+   *     Usage: This should be milliseconds since epoch or an RFC3339 string.
+   *     Examples:
+   *       "update_time = \"2019-06-10T16:07:18-07:00\""
+   *       "update_time = 1560208038000"
+   *
+   *   create_time | `=`, `>`, `<`, `>=`, `<=`
+   *
+   *     Usage: This should be milliseconds since epoch or an RFC3339 string.
+   *     Examples:
+   *       "create_time = \"2019-06-10T16:07:18-07:00\""
+   *       "create_time = 1560208038000"
+   *
    *   iam_policy.policy_blob | '=', ':'
    *   resource_properties | '=', ':', `>`, `<`, `>=`, `<=`
    *   security_marks | '=', ':'
@@ -1725,7 +1787,13 @@ class SecurityCenterClient {
    *   state | '=', ':'
    *   category | '=', ':'
    *   external_uri | '=', ':'
-   *   event_time | `>`, `<`, `>=`, `<=`
+   *   event_time | `=`, `>`, `<`, `>=`, `<=`
+   *
+   *     Usage: This should be milliseconds since epoch or an RFC3339 string.
+   *     Examples:
+   *       "event_time = \"2019-06-10T16:07:18-07:00\""
+   *       "event_time = 1560208038000"
+   *
    *   security_marks | '=', ':'
    *   source_properties | '=', ':', `>`, `<`, `>=`, `<=`
    *
@@ -1936,7 +2004,13 @@ class SecurityCenterClient {
    *   state | '=', ':'
    *   category | '=', ':'
    *   external_uri | '=', ':'
-   *   event_time | `>`, `<`, `>=`, `<=`
+   *   event_time | `=`, `>`, `<`, `>=`, `<=`
+   *
+   *     Usage: This should be milliseconds since epoch or an RFC3339 string.
+   *     Examples:
+   *       "event_time = \"2019-06-10T16:07:18-07:00\""
+   *       "event_time = 1560208038000"
+   *
    *   security_marks | '=', ':'
    *   source_properties | '=', ':', `>`, `<`, `>=`, `<=`
    *
diff --git a/packages/google-cloud-securitycenter/synth.metadata b/packages/google-cloud-securitycenter/synth.metadata
index c0090af385d..2228a8b967e 100644
--- a/packages/google-cloud-securitycenter/synth.metadata
+++ b/packages/google-cloud-securitycenter/synth.metadata
@@ -1,19 +1,19 @@
 {
-  "updateTime": "2019-07-16T21:57:58.657213Z",
+  "updateTime": "2019-07-19T11:21:50.473296Z",
   "sources": [
     {
       "generator": {
         "name": "artman",
-        "version": "0.30.0",
-        "dockerImage": "googleapis/artman@sha256:a44d9fb6fe826ca0ea7d6f7be23c596346bed82ee513a0043f3c068279717439"
+        "version": "0.30.1",
+        "dockerImage": "googleapis/artman@sha256:f1a2e851e5e012c59e1da4125480bb19878f86a4e7fac4f375f2e819956b5aa3"
       }
     },
     {
       "git": {
         "name": "googleapis",
         "remote": "https://github.com/googleapis/googleapis.git",
-        "sha": "96d5a05171e99b6a2378eb0a3423f765351878b7",
-        "internalRef": "258424288"
+        "sha": "f78612e8d008b9678252da84c035da12e92c0093",
+        "internalRef": "258869625"
       }
     },
     {