BUG: BDay() offsetting not behaving as expected

[mhorsley30896]

import pandas as pd
from pandas.tseries.offsets import CDay, BDay

idx = pd.bdate_range("2010/02/01","2010/02/15", freq='6H')

t1 = idx + BDay(offset=pd.Timedelta(3, unit='H'))

t2 = idx + CDay(offset=pd.Timedelta(3, unit='H'))

t1.equals(t2)

False

Problem description

BDay does not seem to be offsetting when a timedelta is supplied.

Expected Output

True

Output of pd.show_versions()

INSTALLED VERSIONS

commit : db08276
python : 3.6.12.final.0
python-bits : 64
OS : Linux
OS-release : 3.10.0-514.6.1.el7.x86_64
Version : #1 SMP Wed Jan 18 13:06:36 UTC 2017
machine : x86_64
processor : x86_64
byteorder : little
LC_ALL : None
LANG : C
LOCALE : None.None

pandas : 1.1.3
numpy : 1.19.2
pytz : 2020.1
dateutil : 2.8.1
pip : 20.2.4
setuptools : 50.3.1.post20201107
Cython : 0.29.21
pytest : 6.1.1
hypothesis : None
sphinx : 3.2.1
blosc : None
feather : None
xlsxwriter : 1.3.7
lxml.etree : 4.6.1
html5lib : 1.1
pymysql : None
psycopg2 : None
jinja2 : 2.11.2
IPython : 7.16.1
pandas_datareader: 0.9.0
bs4 : 4.9.3
bottleneck : 1.3.2
fsspec : 0.8.3
fastparquet : None
gcsfs : None
matplotlib : 3.3.2
numexpr : 2.7.1
odfpy : None
openpyxl : 3.0.5
pandas_gbq : None
pyarrow : None
pytables : None
pyxlsb : None
s3fs : None
scipy : 1.5.2
sqlalchemy : 1.3.20
tables : 3.6.1
tabulate : None
xarray : None
xlrd : 1.2.0
xlwt : 1.3.0
numba : 0.51.2

[phofl]

Hi,

thanks for your report. This returns True on master

/home/developer/PycharmProjects/pandas/pandas/core/arrays/datetimes.py:700: PerformanceWarning: Non-vectorized DateOffset being applied to Series or DatetimeIndex
  warnings.warn(
True

Would you like to contribute a test for this to avoid regression?

[mhorsley30896]

Something like?

def test_bday_ignores_timedeltas():
    idx = pd.bdate_range("2010/02/01","2010/02/15", freq='6H')
    t1 = idx + BDay(offset=pd.Timedelta(3, unit='H'))
    t2 = idx + CDay(offset=pd.Timedelta(3, unit='H'))
    assert t1.equals(t2), 't1 should always equal t2 as behaviour of CDay and BDay equivalent with no calendar'
    pass

[phofl]

Yes essentially, it would be a bit better if you could define expected (t2) without calling a function

[theoniko]

I tried the code snippet from mhorsley30896 with latest master (1.2.0.dev0+1469.g122ae441d) and it returned True. I have not worked in python but i will try to add the test above.

[theoniko]

take

[theoniko]

Hello @phofl
Could you please review pr #38324?