startTime property
The timestamp when the job was started (transitioned to JOB_STATE_PENDING).
Flexible resource scheduling jobs are started with some delay after job creation, so start_time is unset before start and is updated when the job is started by the Cloud Dataflow service. For other jobs, start_time always equals to create_time and is immutable and set by the Cloud Dataflow service.
Implementation
core.String? startTime;