add description to fast forward

Author: feiyang3cat

openapi/openapiv2.json

@@ -21009,7 +21009,7 @@
         },
         "timeSkippingConfig": {
           "$ref": "#/definitions/v1TimeSkippingConfig",
-          "description": "Time-skipping configuration for this workflow execution.\nIf not set, the time-skipping configuration is not updated by this request;\nthe existing configuration is preserved."
+          "description": "Time-skipping configuration for this workflow execution.\nIf not set, the time-skipping configuration is not updated by this request;\nthe existing configuration is preserved.\n\nWhen `fast_forward` is set, time will be fast-forwarded to a future point relative\nto the current workflow timestamp. Each call takes effect, even if\n`fast_forward` is set to the same duration, since the target time is recalculated\nfrom the current timestamp on every call."
         }
       }
     },

openapi/openapiv3.yaml

@@ -19538,6 +19538,11 @@ components:
             Time-skipping configuration for this workflow execution.
              If not set, the time-skipping configuration is not updated by this request;
              the existing configuration is preserved.
+
+             When `fast_forward` is set, time will be fast-forwarded to a future point relative
+             to the current workflow timestamp. Each call takes effect, even if
+             `fast_forward` is set to the same duration, since the target time is recalculated
+             from the current timestamp on every call.
     WorkflowExecutionOptionsUpdatedEventAttributes:
       type: object
       properties:

temporal/api/workflow/v1/message.proto

@@ -588,6 +588,11 @@ message WorkflowExecutionOptions {
     // Time-skipping configuration for this workflow execution.
     // If not set, the time-skipping configuration is not updated by this request;
     // the existing configuration is preserved.
+    //
+    // When `fast_forward` is set, time will be fast-forwarded to a future point relative
+    // to the current workflow timestamp. Each call takes effect, even if
+    // `fast_forward` is set to the same duration, since the target time is recalculated
+    // from the current timestamp on every call.
     TimeSkippingConfig time_skipping_config = 3;
 }