@pytest.fixture(params=[datetime(2011, 1, 1), DatetimeIndex(['2011-01-01', '2011-01-02']), DatetimeIndex(['2011-01-01', '2011-01-02']).tz_localize('US/Eastern'), np.datetime64('2011-01-01'), Timestamp('2011-01-01')], ids=(lambda x: type(x).__name__))
def addend(request):
    return request.param
@pytest.fixture(params=[datetime(2011, 1, 1), DatetimeIndex(['2011-01-01', '2011-01-02']), DatetimeIndex(['2011-01-01', '2011-01-02']).tz_localize('US/Eastern'), np.datetime64('2011-01-01'), Timestamp('2011-01-01')], ids=(lambda x: type(x).__name__))
def addend(request):
    return request.param