What is the meaning of the error "DAG is missing the start_date" when using a for loop to add tasks dynamically to an airflow DAG?

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The error "DAG is missing the startdate" means that the DAG (Directed Acyclic Graph) object being created does not have a startdate attribute specified. The startdate attribute is a required parameter that determines the date and time when the DAG is first run. When using a for loop to add tasks dynamically to a DAG, each task must specify a startdate relative to the DAG's startdate. Therefore, the DAG object must have a startdate specified in order for the tasks to be added correctly.