
**Apache Airflow version**:

master

**What happened**:

https://github.com/apache/airflow/blob/master/airflow/models/baseoperator.py#L356 --> should be timedelta not datetime


airflow/models/baseoperator.py
upstream = True
        else:
            upstream = False
        if not self._dag:
            return self.priority_weight
        from airflow.models.dag import DAG
        dag: DAG = self._dag
        return self.priority_weight + sum(
            map(
                lambda task_id: dag.task_dict[task_id].priority_weight,
                self.get_flat_relative_ids(upstream=upstream),
            )
        )
    @cached_property
    def operator_extra_link_dict(self) -> Dict[str, Any]:
        """Returns dictionary of all extra links for the operator"""
        op_extra_links_from_plugin: Dict[str, Any] = {}
        from airflow import plugins_manager
        plugins_manager.initialize_extra_operators_links_plugins()
        if plugins_manager.operator_extra_links is None:
            raise AirflowException("Can't load operators")
        for ope in plugins_manager.operator_extra_links:
            if ope.operators and self.__class__ in ope.operators:
                op_extra_links_from_plugin.update({ope.name: ope})
        operator_extra_links_all = {link.name: link for link in self.operator_extra_links}
        
        operator_extra_links_all.update(op_extra_links_from_plugin)
        return operator_extra_links_all
    @cached_property
    def global_operator_extra_link_dict(self) -> Dict[str, Any]: