title: Airflow schedule interval stuck at '1 day, 0:00:0'
body: <p>I need to change the time my DAG runs at to be midday. I followed the advice from various questions on here and deleted the DAG and uploaded a renamed version with a new <code>dag_id</code>. Even though the original DAG was renamed from, say, dag_1.py to new_dag_1.py, THE <code>dag_id</code> changed, and the schedule interval was changed from '@daily' to '0 12 * * *' when I upload this new DAG version the schedule part of the homepage for this dag still says '1 day, 0:00:00'.</p>
  <p>I uploaded a completely different DAG with these parameters and the schedule interval correctly shows '0 12 * * *' so there must be something in the changed DAG or some metadata that is preventing Airflow from seeing it as new. Other than the name of the dag file that I changed and the changed <code>dag_id</code> is there anything else I should have changed for Airflow to let me set this to run at a different time?</p>
  <p>EDIT: I have recreated this problem with some generic code:</p>
  <p>Here is the first version of the dag: dag_1.py</p>
  <pre><code>import airflow
  import datetime
  import logging
  from airflow.utils.task_group import TaskGroup
  from airflow.operators.dummy import DummyOperator
  
  YESTERDAY = datetime.datetime.now() - datetime.timedelta(days=1)
  
  default_args = {
      'owner': 'my_name',
      'depends_on_past': False,
      'email': ['my_email'],
      'email_on_failure': False,
      'email_on_retry': False,
      'retries': 0 ,
      'slack_conn_id': 'slack_conn',
      'start_date': YESTERDAY,
      'project_id': 'my_project',
      'dataset_id': 'my_dataset',
      'schedule_interval': '@daily',
  }
  
  with airflow.DAG(
          'test_cron',
          catchup=False,
          default_args=default_args,
          tags=['example']
      ) as dag:
  
      my_empty_operator = DummyOperator(
          task_id='empty_task',
          dag=dag,
      )
  
      my_empty_operator
  </code></pre>
  <p>And the updated version dag_1_2.py</p>
  <pre><code>import airflow
  import datetime
  import logging
  from airflow.utils.task_group import TaskGroup
  from airflow.operators.dummy import DummyOperator
  
  YESTERDAY = datetime.datetime.now() - datetime.timedelta(days=1)
  
  default_args = {
      'owner': 'my_name',
      'depends_on_past': False,
      'email': ['my_email'],
      'email_on_failure': False,
      'email_on_retry': False,
      'retries': 0 ,
      'slack_conn_id': 'slack_conn',
      'start_date': YESTERDAY,
      'project_id': 'my_project',
      'dataset_id': 'my_dataset',
      'schedule_interval': '0 12 * * *',
  }
  
  with airflow.DAG(
          'test_cron_2',
          catchup=False,
          default_args=default_args,
          tags=['example']
      ) as dag:
  
      my_empty_operator = DummyOperator(
          task_id='empty_task',
          dag=dag,
      )
  
      my_empty_operator
  </code></pre>
  <p>Note I have changed
  1.the name of the file
  2.the name of the dag_id
  3.the schedule_interval</p>
  <p>However the new DAG, dag_1_2.py still shows on the UI as having a schedule of 1 day, 0:00:00. How is this possible? For all intents and purposes this is a new DAG (or so it seems?)</p>