from datetime import datetime


def valid_after_from_network_statuses(network_statuses):
    """Obtain the consensus Valid-After datetime from the ``document``
    attribute of a ``stem.descriptor.RouterStatusEntryV3``.

    :param list network_statuses:

    returns datetime:
    """
    for ns in network_statuses:
        document = getattr(ns, 'document', None)
        if document:
            valid_after = getattr(document, 'valid_after', None)
            if valid_after:
                return valid_after
    return datetime.utcnow().replace(microsecond=0)