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.. _howto/operator:BranchDateTimeOperator:

BranchDateTimeOperator
======================

Use the :class:`~airflow.operators.datetime.BranchDateTimeOperator` to branch into one of two execution paths depending on whether the date and/or time of execution falls into the range given by two target arguments.

.. exampleinclude:: /../../airflow/example_dags/example_branch_datetime_operator.py
    :language: python
    :start-after: [START howto_branch_datetime_operator]
    :end-before: [END howto_branch_datetime_operator]

The target parameters, ``target_upper`` and ``target_lower``, can receive a ``datetime.datetime``, a ``datetime.time``, or ``None``. When a ``datetime.time`` object is used, it will be combined with the current date in order to allow comparisons with it. In the event that ``target_upper`` is set to a ``datetime.time`` that occurs before the given ``target_lower``, a day will be added to ``target_upper``. This is done to allow for time periods that span over two dates.

.. exampleinclude:: /../../airflow/example_dags/example_branch_datetime_operator.py
    :language: python
    :start-after: [START howto_branch_datetime_operator_next_day]
    :end-before: [END howto_branch_datetime_operator_next_day]

If a target parameter is set to ``None``, the operator will perform a unilateral comparison using only the non-``None`` target. Setting both ``target_upper`` and ``target_lower`` to ``None`` will raise an exception.