### Discussed in https://github.com/apache/airflow/discussions/33345

<div type='discussions-op-text'>

<sup>Originally posted by **vuphamcs** August 11, 2023</sup>
### Description

Is there a variable similar to `prev_start_date_success` but for the previous DAG run’s completion date? The value I’m hoping to retrieve to use within the next DAG run is `2023-08-10 16:04:30`

![image](https://github.com/apache/airflow/assets/1600760/9e2af349-4c3e-47e1-8a1a-9d8827b56f57)


### Use case/motivation

One particular use case is to help guarantee that the next DAG run only queries data that was inserted during the existing DAG run, and not the past DAG run.

```python
prev_ts = context['prev_end_date_success']

sql = f"SELECT * FROM results WHERE created_at > {context['prev_end_date_success']}"
```

### Related issues

_No response_

### Are you willing to submit a PR?

- [ ] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)
</div>
return "branch_1"
            branch_op = self.opcls(task_id=self.task_id, python_callable=f, **self.default_kwargs())
            branches = [self.branch_1, self.branch_2]
            branch_op >> branches
        dr = self.create_dag_run()
        branch_op.run(start_date=self.default_date, end_date=self.default_date)
        for task in branches:
            task.run(start_date=self.default_date, end_date=self.default_date)
        expected_states = {
            self.task_id: State.SUCCESS,
            "branch_1": State.SUCCESS,
            "branch_2": State.SKIPPED,
        }
        self.assert_expected_task_states(dr, expected_states)
        
        tis = dr.get_task_instances()
        children_tis = [ti for ti in tis if ti.task_id in branch_op.get_direct_relative_ids()]
        with create_session() as session:
            clear_task_instances(children_tis, session=session, dag=branch_op.dag)
        
        for task in branches:
            task.run(start_date=self.default_date, end_date=self.default_date)
        
        self.assert_expected_task_states(dr, expected_states)
    def test_raise_exception_on_no_accepted_type_return(self):