BUG/API: QuarterBegin n=0 #11406
closes #11406 - makes `QuarterBegin` for `n=0` match Month/Year.

xref #11427 - once this is merged the failures there should pass - there is also a little more documentation about general offset semantics in that PR.

cc @cancan101 
cc @seth-p

look ok to you?
 Looks fine to me,  though I don't recall ever commenting on offsets.

On Dec 7, 2015, at 1:24 PM, Jeff Reback <notifications@github.com<mailto:notifications@github.com>> wrote:

cc @cancan101https://github.com/cancan101
cc @seth-phttps://github.com/seth-p

look ok to you?

## 

Reply to this email directly or view it on GitHubhttps://github.com/pydata/pandas/pull/11777#issuecomment-162493690.
 From #8435 does this now return something sensible?

```
pd.Timestamp('11/2/2012', tz='US/Eastern') + pd.tseries.offsets.QuarterBegin()
Out[29]: Timestamp('2012-12-01 00:00:00-0500', tz='US/Eastern')
pd.Timestamp('11/2/2012', tz='US/Eastern') + pd.tseries.offsets.QuarterEnd()
Out[30]: Timestamp('2012-12-31 00:00:00-0500', tz='US/Eastern')
```
 cc @MichaelWS
 Looks sensible to me
 @rockg I believe that @chris-b1 next PR, #11370 wiill address that (and is dependent on this PR)
 merged via https://github.com/pydata/pandas/commit/56fd4e34a1d8ec8e82bcaa37ba0237ec94431834

thanks!
