title: apache airflow scheduler not working properly
body: <p>I've created some <code>DAG</code>s, and I tried to put it on scheduler. I want to run all the tasks in the DAG after exact 24 hours.
  I tried to do something like this.</p>
  
  <pre><code>DEFAULT_ARGS        = {
  'owner'           : 'mubin',
  'depends_on_past' : False,
  'start_date'      : datetime(2017, 4, 24, 14, 30),
  'retries'         : 5,
  'retry_delay'     : timedetla(1),
  }
  SCHEDULE_INTERVAL      = timedelta(minutes=1440)
  # SCHEDULE_INTERVAL    = timedelta(hours=24)
  # SCHEDULE_INTERVAL    = timedelta(days=1)
  dag = DAG('StandardizeDataDag',
      default_args       = DEFAULT_ARGS,
      schedule_interval  = SCHEDULE_INTERVAL
  )
  </code></pre>
  
  <p>I tried to put different intervals, but not any working. However if I try to reset db <code>airflow resetdb -y</code> and then run <code>airflow initdb</code>, it works for once. then after that, scheduler isn't able to run it.
  <strong>airflow version: v1.8.0</strong></p>
  
  <p>PS. <code>airflow scheduler</code> is executed via <code>root</code></p>
  
  <p>can anybody point me what I'm doing wrong?</p>