diff --git a/openapi/openapiv2.json b/openapi/openapiv2.json
index 6c2cdb0e2..f990c48e7 100644
--- a/openapi/openapiv2.json
+++ b/openapi/openapiv2.json
@@ -13559,6 +13559,11 @@
         "executionDuration": {
           "type": "string",
           "description": "The difference between close time and scheduled time.\nThis field is only populated if the activity is closed."
+        },
+        "executionTime": {
+          "type": "string",
+          "format": "date-time",
+          "description": "The time at which the first activity task is made available for dispatch, computed as\n`schedule_time + start_delay`. Same as `schedule_time` if `start_delay` is not set."
         }
       },
       "description": "Limited activity information returned in the list response.\nWhen adding fields here, ensure that it is also present in ActivityExecutionInfo (note that it\nmay already be present in ActivityExecutionInfo but not at the top-level)."
diff --git a/openapi/openapiv3.yaml b/openapi/openapiv3.yaml
index f33babffa..dad8d0ec0 100644
--- a/openapi/openapiv3.yaml
+++ b/openapi/openapiv3.yaml
@@ -9913,6 +9913,12 @@ components:
           description: |-
             The difference between close time and scheduled time.
              This field is only populated if the activity is closed.
+        executionTime:
+          type: string
+          description: |-
+            The time at which the first activity task is made available for dispatch, computed as
+             `schedule_time + start_delay`. Same as `schedule_time` if `start_delay` is not set.
+          format: date-time
       description: |-
         Limited activity information returned in the list response.
          When adding fields here, ensure that it is also present in ActivityExecutionInfo (note that it
diff --git a/temporal/api/activity/v1/message.proto b/temporal/api/activity/v1/message.proto
index db134d301..928ff787b 100644
--- a/temporal/api/activity/v1/message.proto
+++ b/temporal/api/activity/v1/message.proto
@@ -223,6 +223,9 @@ message ActivityExecutionListInfo {
     // The difference between close time and scheduled time.
     // This field is only populated if the activity is closed.
     google.protobuf.Duration execution_duration = 11;
+    // The time at which the first activity task is made available for dispatch, computed as
+    // `schedule_time + start_delay`. Same as `schedule_time` if `start_delay` is not set.
+    google.protobuf.Timestamp execution_time = 12;
 }
 
 // CallbackInfo contains the state of an attached activity callback.