public com.google.protobuf.Timestamp getStartTime() {
      if (startTimeBuilder_ == null) {
        return startTime_ == null ? com.google.protobuf.Timestamp.getDefaultInstance() : startTime_;
      } else {
        return startTimeBuilder_.getMessage();
      }
    }
<pre>
Output only. Marks the beginning of execution.
</pre>

<code>.google.protobuf.Timestamp start_time = 2 [(.google.api.field_behavior) = OUTPUT_ONLY];
</code>

@return The startTime.
java-workflow-executions/proto-google-cloud-workflow-executions-v1beta/src/main/java/com/google/cloud/workflows/executions/v1beta/Execution.java