Fix comparing two date strings when they may or may not have microseconds

I'm getting errors with this function:

def compare_dates(date1: str, date2: str) -> str:
    date1_obj = datetime.strptime(date1, "%Y-%m-%dT%H:%M:%S")
    date2_obj = datetime.strptime(date2, "%Y-%m-%dT%H:%M:%S")
    return date1 if date1_obj > date2_obj else date2

Because the input sometimes includes microseconds. Is there a clearer way of dealing with this than what I've done?

def compare_dates(date1: str, date2: str) -> str:
    date_format = "%Y-%m-%dT%H:%M:%S"
    date1_obj = datetime.strptime(date1.split(".")[0], date_format)
    date2_obj = datetime.strptime(date2.split(".")[0], date_format)
    date1_obj = date1_obj.replace(microsecond=0)
    date2_obj = date2_obj.replace(microsecond=0)
    return date1 if date1_obj > date2_obj else date2