BUG: Breaking change to offsets.pyx - quarter offset classes
Set default months for `BQuarterEnd`, `BQuarterBegin`, `QuarterEnd`, `QuarterBegin` classes in order; rename `startingMonth` parameter to `month` for those classes.
Addresses #8435 and #5307

- [ ] closes #8435 #5307
- [x] tests added / passed
- [x] Ensure all linting tests pass, see [here](https://pandas.pydata.org/pandas-docs/dev/development/contributing.html#code-standards) for how to run them
- [ ] whatsnew entry

pls just one PR - just push to the same one if changing  > pls just one PR - just push to the same one if changing

But this one has different scope from #39887 . The change regarding months alone in #39887 should hopefully be easier to process, and less breaking. ok that's fine

you always need a test does this handle #5307? > does this handle #5307?

Not at present. I'd like to cover it as well - please let me know if that's OK. > does this handle #5307?

It does now. Hello @Pawel-Kranzberg! Thanks for updating this PR. We checked the lines you've touched for [PEP 8](https://www.python.org/dev/peps/pep-0008) issues, and found:























There are currently no PEP 8 issues detected in this Pull Request. Cheers! :beers: 

##### Comment last updated at 2021-05-06 07:50:12 UTC > can you add a sub-section in the whatsnew 1.3 api breaking changes to indicate what a user would except (aside from the deprection)

Description drafted and added. > so you are adding a new parameter 'month', so now we have the confusing 'startingMonth' and 'month'. I would rather deprecate 'startingMonth', then add new; not even sure 'month' is a good name here. can you write a sample whatsnew note indicate what the change is here from a user POV.

BTW, maybe `anchor` would be a better replacement name? This pull request is stale because it has been open for thirty days with no activity. Please update or respond to this comment if you're still interested in working on this. > I would _really_ like to do the deprecation first and separate

@Pawel-Kranzberg what's the status. close this and open separate PRs? > > I would _really_ like to do the deprecation first and separate
> 
> @Pawel-Kranzberg what's the status. close this and open separate PRs?

Yes, I plan to do so next week. Thanks for the PR, but it has appeared to have gone stale. Closing due to inactivity, but we would be happy to take a new PR working on the deprecation first.