BUG: resampling with origin='end_day' raises ValueError: Values falls before first bin

[mkp-gebensleben]

Pandas version checks

• I have checked that this issue has not already been reported.

• I have confirmed this bug exists on the latest version of pandas.

• I have confirmed this bug exists on the master branch of pandas.

Reproducible Example

import pandas as pd

idx = pd.date_range(
    start='2021-04-22 01:00:00+00:00',
    end='2021-04-28 01:00:00+00:00',
    freq='1d'
)

df = pd.DataFrame(index=idx, data=range(len(idx)))

result = df.resample(rule='7d', origin='end_day').min()

Issue Description

Using origin='end_day' when resampling raises a ValueError. I don't understand the error message.

Traceback

Traceback (most recent call last):
  File "C:\Users\User.Name\.virtualenvs\MyEnv-SwK0JD0-\lib\site-packages\IPython\core\interactiveshell.py", line 3457, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "<ipython-input-28-b959ed20b9fd>", line 11, in <module>
    result = df.resample(rule='7d', origin='end_day').min()
  File "C:\Users\User.Name\.virtualenvs\MyEnv-SwK0JD0-\lib\site-packages\pandas\core\frame.py", line 10350, in resample
    return super().resample(
  File "C:\Users\User.Name\.virtualenvs\MyEnv-SwK0JD0-\lib\site-packages\pandas\core\generic.py", line 8126, in resample
    return get_resampler(
  File "C:\Users\User.Name\.virtualenvs\MyEnv-SwK0JD0-\lib\site-packages\pandas\core\resample.py", line 1382, in get_resampler
    return tg._get_resampler(obj, kind=kind)
  File "C:\Users\User.Name\.virtualenvs\MyEnv-SwK0JD0-\lib\site-packages\pandas\core\resample.py", line 1552, in _get_resampler
    return DatetimeIndexResampler(obj, groupby=self, kind=kind, axis=self.axis)
  File "C:\Users\User.Name\.virtualenvs\MyEnv-SwK0JD0-\lib\site-packages\pandas\core\resample.py", line 158, in __init__
    self.binner, self.grouper = self._get_binner()
  File "C:\Users\User.Name\.virtualenvs\MyEnv-SwK0JD0-\lib\site-packages\pandas\core\resample.py", line 241, in _get_binner
    binner, bins, binlabels = self._get_binner_for_time()
  File "C:\Users\User.Name\.virtualenvs\MyEnv-SwK0JD0-\lib\site-packages\pandas\core\resample.py", line 1113, in _get_binner_for_time
    return self.groupby._get_time_bins(self.ax)
  File "C:\Users\User.Name\.virtualenvs\MyEnv-SwK0JD0-\lib\site-packages\pandas\core\resample.py", line 1609, in _get_time_bins
    bins = lib.generate_bins_dt64(
  File "pandas\_libs\lib.pyx", line 809, in pandas._libs.lib.generate_bins_dt64
ValueError: Values falls before first bin

Expected Behavior

The resample docs say

‘end_day’: origin is the ceiling midnight of the last day

so I expected origin='end_day' to behave like origin=df.index.max().ceil('1d').
However, only the first approach raises an error.

>>> df.resample(rule='7d', origin=df.index.max().ceil('1d')).min() 
                           0
2021-04-22 00:00:00+00:00  0

Installed Versions

INSTALLED VERSIONS
------------------
commit : 66e3805
python : 3.8.7.final.0
python-bits : 64
OS : Windows
OS-release : 10
Version : 10.0.19041
machine : AMD64
processor : AMD64 Family 23 Model 96 Stepping 1, AuthenticAMD
byteorder : little
LC_ALL : None
LANG : None
LOCALE : de_DE.cp1252
pandas : 1.3.5
numpy : 1.21.4
pytz : 2021.3
dateutil : 2.8.2
pip : 21.0.1
setuptools : 53.0.0
Cython : None
pytest : 6.2.3
hypothesis : None
sphinx : None
blosc : None
feather : None
xlsxwriter : None
lxml.etree : None
html5lib : None
pymysql : None
psycopg2 : 2.9.2 (dt dec pq3 ext lo64)
jinja2 : 3.0.3
IPython : 7.30.1
pandas_datareader: None
bs4 : None
bottleneck : None
fsspec : None
fastparquet : None
gcsfs : None
matplotlib : 3.4.1
numexpr : None
odfpy : None
openpyxl : None
pandas_gbq : None
pyarrow : None
pyxlsb : None
s3fs : None
scipy : 1.7.3
sqlalchemy : 1.4.28
tables : None
tabulate : 0.8.9
xarray : None
xlrd : 2.0.1
xlwt : None
numba : None

[mkp-gebensleben]

The actual equivalent of

df.resample(rule='7d', origin='end_day').min()

is

df.resample(rule='7d', origin=df.index.max().ceil('1d'), closed='right', label='right').min()

for which the same ValueError is raised.

So there are two issues

1. The docs should mention that 'end' and 'end_day' override closed and label (if they are None).
2. I still don't understand the ValueError. Why does resample not add bins as needed until all timestamps of the index fall into a bin?

[mkp-gebensleben]

Related stackoverflow questions

https://stackoverflow.com/questions/70436226/resampling-raises-valueerror-values-falls-before-first-bin

https://stackoverflow.com/questions/70436514/timestamp-binning-mechanics-when-resampling