Fix for #3719

[jstenar]

%-d is not a valid strftime format on windows.

[ivanov]

I don't know if it'll work on windows, but I think we'd want %e here, instead (replace with a space instead of a leading zero). Try it with datetime.datetime(1921,01,01).strftime("%B %e, %Y")

[dhirschfeld]

I'm seeing the same thing on Python 2.7 / Win32:

In [8]: pd.datetime(1921,01,01).strftime("%B %e, %Y")
Traceback (most recent call last):

  File "<ipython-input-8-509fca1c6706>", line 1, in <module>
    pd.datetime(1921,01,01).strftime("%B %e, %Y")

ValueError: Invalid format string


In [9]: pd.datetime(1921,01,01).strftime("%B %-d, %Y")
Traceback (most recent call last):

  File "<ipython-input-9-f5acce1b2c70>", line 1, in <module>
    pd.datetime(1921,01,01).strftime("%B %-d, %Y")

ValueError: Invalid format string


In [10]: pd.datetime(1921,01,01).strftime("%B %d, %Y")
Out[10]: 'January 01, 1921'

[ivanov]

ok, based on @dhirschfeld's feedback, %e isn't an option on windows, so I'm +1 on merging this. Will just let @jdfreder and @Carreau check in here if there are other consideration here before making the merge.

[jdfreder]

I hate the fact that the - doesn't work on windows. I'm sad there isn't an alternative format specifier (from what I could find). The only option that would achieve what we want is using str.format() to insert the day as an integer... But that would be a bit confusing to read...

d = pd.datetime(1921,01,01)
d.strftime("%B {0}, %Y").format(d.day)

@ivanov @dhirschfeld @Carreau If this is just too ugly to bare, I'm 👍 for merging. Just note, this shows up as "June 01, 1990" in the Sphinx documents

[minrk]

Merging now, I think this is the right fix.

[ivanov]

oh man, how do folks feel about doing %d only for windows, and having the saner and cleaner %-d. I can have a PR ready

[minrk]

PR if you feel like it.