Validates that the input can be converted to a datetime. Returns a
        Python datetime.datetime object.

def to_python(self, value):
        """
        Validates that the input can be converted to a datetime. Returns a
        Python datetime.datetime object.
        """
        if value in validators.EMPTY_VALUES:
            return None
        if isinstance(value, datetime.datetime):
            return value
        if isinstance(value, datetime.date):
            return datetime.datetime(value.year, value.month, value.day)
        if isinstance(value, list):
            # Input comes from a 2 SplitDateTimeWidgets, for example. So,
            # it's four components: start date and time, and end date and time.
            if len(value) != 4:
                raise ValidationError(self.error_messages['invalid'])
            if value[0] in validators.EMPTY_VALUES and value[1] in \
                    validators.EMPTY_VALUES and value[2] in \
                    validators.EMPTY_VALUES and value[3] in \
                    validators.EMPTY_VALUES:
                return None
            start_value = '%s %s' % tuple(value[:2])
            end_value = '%s %s' % tuple(value[2:])

        start_datetime = None
        end_datetime = None
        for format in self.input_formats or formats.get_format(\
                'DATETIME_INPUT_FORMATS'):
            try:
                start_datetime = datetime.datetime(*time.strptime(\
                        start_value, format)[:6])
            except ValueError:
                continue

        for format in self.input_formats or formats.get_format(\
                'DATETIME_INPUT_FORMATS'):
            try:
                end_datetime = datetime.datetime(*time.strptime(\
                        end_value, format)[:6])
            except ValueError:
                continue

        return (start_datetime, end_datetime)