def birthdays():
    dates = [
        date(1964, 12, 30),
        date(1964, 12, 31),
        date(1964, 1, 1),
        date(1964, 1, 2),
        date(1964, 1, 9),
        date(1964, 1, 10),
        date(1964, 1, 11),
        date(1964, 1, 12),
        date(1964, 1, 30),
        date(1964, 1, 31),
        date(1964, 2, 1),
        date(1964, 2, 2),
        date(1964, 2, 27),
        date(1964, 2, 28),
        date(1964, 2, 29),
        date(1964, 3, 1),
        date(1964, 3, 2)]

    attendees = []
    for d in dates:
        attendees.append(Attendee(
            placeholder=True,
            first_name='Born on',
            last_name=d.strftime('%B %-d, %Y'),
            ribbon=c.VOLUNTEER_RIBBON,
            staffing=True,
            birthdate=d))

    ids = []
    with Session() as session:
        session.bulk_insert(attendees)
        ids = [a.id for a in attendees]

    yield ids

    with Session() as session:
        session.query(Attendee).filter(Attendee.id.in_(ids)).delete(
            synchronize_session=False)