TypeError: unsupported type for timedelta days component: datetime.datetime
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I am trying to perform some date arithmetic in a function.

    from datetime import datetime, timedelta
    
    def foo(date1, summing_period):
        current_period_start_date = date1 - timedelta(days=summing_period)
        # Line above causes the error:
        # TypeError: unsupported type for timedelta days component: datetime.datetime


First arg is a datetime obj and 2nd arg is an integer

What is causing this error, and how do I fix it?
