html_url,issue_url,id,node_id,user,created_at,updated_at,author_association,body,reactions,performed_via_github_app,issue
https://github.com/pydata/xarray/pull/5876#issuecomment-1010114336,https://api.github.com/repos/pydata/xarray/issues/5876,1010114336,IC_kwDOAMm_X848NR8g,6628425,2022-01-11T16:06:33Z,2022-01-11T16:06:33Z,MEMBER,Thanks @pierreloicq!,"{""total_count"": 3, ""+1"": 1, ""-1"": 0, ""laugh"": 0, ""hooray"": 1, ""confused"": 0, ""heart"": 1, ""rocket"": 0, ""eyes"": 0}",,1030492705
https://github.com/pydata/xarray/pull/5876#issuecomment-1008312049,https://api.github.com/repos/pydata/xarray/issues/5876,1008312049,IC_kwDOAMm_X848GZ7x,6628425,2022-01-09T14:51:33Z,2022-01-09T17:53:08Z,MEMBER,"@dcherian @mathause @andersy005 given a DataArray of times with missing values, do you have any thoughts on what the preferred result of `da.dt.season` would be?

One option would be to return `np.nan` in place of the missing time values:

```
In [3]: times = [np.datetime64(""NaT""), np.datetime64(""2000-01-01"")]

In [4]: da = xr.DataArray(times, dims=[""x""])

In [5]: da.dt.season
Out[5]:
<xarray.DataArray 'season' (x: 2)>
array([nan, 'DJF'], dtype=object)
Dimensions without coordinates: x
```

This would be somewhat in line with how pandas handles this in other contexts (e.g. https://github.com/pydata/xarray/pull/5876#discussion_r734447120).  But this sort of awkwardly returns a DataArray of mixed types.  Another option, and this is how @pierreloicq implemented things originally, would be to simply return a string label for missing values, e.g.

```
In [5]: da.dt.season
Out[5]:
<xarray.DataArray 'season' (x: 2)>
array(['nan', 'DJF'], dtype='<U32')
Dimensions without coordinates: x
```

As I've thought about this more, this feels nicer, because the types are consistent and ""season"" is just a category label, and `""nan""` categorizes these values just as well as `np.nan`.  Do you agree?","{""total_count"": 3, ""+1"": 3, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,1030492705
https://github.com/pydata/xarray/pull/5876#issuecomment-973649826,https://api.github.com/repos/pydata/xarray/issues/5876,973649826,IC_kwDOAMm_X846CLei,6628425,2021-11-19T01:41:05Z,2021-11-19T01:41:05Z,MEMBER,No worries about the cftime tests by the way -- how to best handle missing values in that context is still somewhat of an open question (https://github.com/Unidata/cftime/issues/145).,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,1030492705