fix for BUG: grouping with tz-aware: Values falls after last bin
- [ ] closes #24972 
- [ ] tests added / passed
- [ ] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24973?src=pr&el=h1) Report
> Merging [#24973](https://codecov.io/gh/pandas-dev/pandas/pull/24973?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/2b16e2e6c5a298396727fc2e66a60edf1eb13bf9?src=pr&el=desc) will **decrease** coverage by `49.48%`.
> The diff coverage is `0%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/24973/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/24973?src=pr&el=tree)

```diff
@@             Coverage Diff             @@
##           master   #24973       +/-   ##
===========================================
- Coverage   92.38%   42.89%   -49.49%     
===========================================
  Files         166      166               
  Lines       52398    52401        +3     
===========================================
- Hits        48406    22476    -25930     
- Misses       3992    29925    +25933
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `?` | |
| #single | `42.89% <0%> (-0.01%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/24973?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/resample.py](https://codecov.io/gh/pandas-dev/pandas/pull/24973/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvcmVzYW1wbGUucHk=) | `23.19% <0%> (-74.05%)` | :arrow_down: |
| [pandas/io/formats/latex.py](https://codecov.io/gh/pandas-dev/pandas/pull/24973/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2Zvcm1hdHMvbGF0ZXgucHk=) | `0% <0%> (-100%)` | :arrow_down: |
| [pandas/core/categorical.py](https://codecov.io/gh/pandas-dev/pandas/pull/24973/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvY2F0ZWdvcmljYWwucHk=) | `0% <0%> (-100%)` | :arrow_down: |
| [pandas/io/sas/sas\_constants.py](https://codecov.io/gh/pandas-dev/pandas/pull/24973/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL3Nhcy9zYXNfY29uc3RhbnRzLnB5) | `0% <0%> (-100%)` | :arrow_down: |
| [pandas/tseries/plotting.py](https://codecov.io/gh/pandas-dev/pandas/pull/24973/diff?src=pr&el=tree#diff-cGFuZGFzL3RzZXJpZXMvcGxvdHRpbmcucHk=) | `0% <0%> (-100%)` | :arrow_down: |
| [pandas/tseries/converter.py](https://codecov.io/gh/pandas-dev/pandas/pull/24973/diff?src=pr&el=tree#diff-cGFuZGFzL3RzZXJpZXMvY29udmVydGVyLnB5) | `0% <0%> (-100%)` | :arrow_down: |
| [pandas/io/formats/html.py](https://codecov.io/gh/pandas-dev/pandas/pull/24973/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2Zvcm1hdHMvaHRtbC5weQ==) | `0% <0%> (-99.35%)` | :arrow_down: |
| [pandas/core/groupby/categorical.py](https://codecov.io/gh/pandas-dev/pandas/pull/24973/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZ3JvdXBieS9jYXRlZ29yaWNhbC5weQ==) | `0% <0%> (-95.46%)` | :arrow_down: |
| [pandas/io/sas/sas7bdat.py](https://codecov.io/gh/pandas-dev/pandas/pull/24973/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL3Nhcy9zYXM3YmRhdC5weQ==) | `0% <0%> (-91.17%)` | :arrow_down: |
| [pandas/io/sas/sas\_xport.py](https://codecov.io/gh/pandas-dev/pandas/pull/24973/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL3Nhcy9zYXNfeHBvcnQucHk=) | `0% <0%> (-90.15%)` | :arrow_down: |
| ... and [124 more](https://codecov.io/gh/pandas-dev/pandas/pull/24973/diff?src=pr&el=tree-more) | |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24973?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24973?src=pr&el=footer). Last update [2b16e2e...0454dc3](https://codecov.io/gh/pandas-dev/pandas/pull/24973?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24973?src=pr&el=h1) Report
> Merging [#24973](https://codecov.io/gh/pandas-dev/pandas/pull/24973?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/6449bc15758325bd753bbb13160ee825197023c3?src=pr&el=desc) will **increase** coverage by `<.01%`.
> The diff coverage is `100%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/24973/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/24973?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #24973      +/-   ##
==========================================
+ Coverage   92.38%   92.38%   +<.01%     
==========================================
  Files         166      166              
  Lines       52400    52401       +1     
==========================================
+ Hits        48409    48410       +1     
  Misses       3991     3991
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.8% <100%> (ø)` | :arrow_up: |
| #single | `42.88% <10%> (-0.01%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/24973?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/resample.py](https://codecov.io/gh/pandas-dev/pandas/pull/24973/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvcmVzYW1wbGUucHk=) | `97.24% <100%> (ø)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24973?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24973?src=pr&el=footer). Last update [6449bc1...47eb40b](https://codecov.io/gh/pandas-dev/pandas/pull/24973?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 Could you check if this solution https://github.com/pandas-dev/pandas/issues/24972#issuecomment-458020507 passes the CI? I think it's closer to fixing the root cause of the bug. Minor comment; but after LGTM do we also have the equivalent test for resample @mroeschke  (I think this answer might be yes). @ahcub if so, then we'd like to co-locate these tests. did this work in 0.23.4? @jreback The DST resample tests are located around here:

https://github.com/pandas-dev/pandas/blob/3fd47fef4442a9a116e9bf37b607332551924179/pandas/tests/resample/test_datetime_index.py#L1254

The added test should take the exact same path as analogous resample path. thanks @mroeschke 

@ahcub I would move the test right below that one (alternatively, you can put a cross reference in both tests, e.g. a comment that says the corresponding test is ........) it did work in 0.23.4, yes moved the tests is everything good now? lgtm. @ahcub can you merge master and fix the conflict in the whatsnew. ping on green. lgtm. ping on green. it is all green @jreback  Thanks @ahcub. Owee, I'm MrMeeseeks, Look at me.

There seem to be a conflict, please backport manually. Here are approximate instructions:

1. Checkout backport branch and update it.

```
$ git checkout 0.24.x
$ git pull
```

2. Cherry pick the first parent branch of the this PR on top of the older branch:
```
$ git cherry-pick -m1 abf0824200a34c00f6a20b283bbb968f2c2d288f
```

3. You will likely have some merge/cherry-pick conflict here, fix them and commit:

```
$ git commit -am 'Backport PR #24973: fix for BUG: grouping with tz-aware: Values falls after last bin'
```

4. Push to a named branch :

```
git push YOURFORK 0.24.x:auto-backport-of-pr-24973-on-0.24.x
```

5. Create a PR against branch 0.24.x, I would have named this PR:

> "Backport PR #24973 on branch 0.24.x"

And apply the correct labels and milestones.

Congratulation you did some good work ! Hopefully your backport PR will be tested by the continuous integration and merged soon!

If these instruction are inaccurate, feel free to [suggest an improvement](https://github.com/MeeseeksBox/MeeseeksDev).
                 Doing the manual backport now.