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/3283#issuecomment-541046819,https://api.github.com/repos/pydata/xarray/issues/3283,541046819,MDEyOklzc3VlQ29tbWVudDU0MTA0NjgxOQ==,12229877,2019-10-11T12:38:06Z,2019-10-11T12:38:06Z,CONTRIBUTOR,"> The datetime64 & timedelta64 cases don't roundtrip completely, so there are test failures. I've added these in a separate commit at the end, so it's easy to cut that back out if you prefer.

The basic problem seems to be that Hypothesis is generating `timedelta64[Y]`, but Xarray is dealing with `timedelta64[ns]`:

```
____________________________ test_netcdf_roundtrip _____________________________
tmp_path = PosixPath('/tmp/pytest-of-vsts/pytest-0/test_netcdf_roundtrip0')
data = data(...), arr = array([293], dtype='timedelta64[Y]')
        ...
        with xr.open_dataset(tmp_path / ""test.nc"") as roundtripped:
>           xr.testing.assert_identical(original, roundtripped)
E           AssertionError: Left and right Dataset objects are not identical
E           
E           Differing data variables:
E           L   data     (0) timedelta64[ns] -106488 days +01:41:02.290448
E           R   data     (0) timedelta64[ns] -106488 days +01:41:02.290449

properties/test_netcdf_roundtrip.py:51: AssertionError
---------------------------------- Hypothesis ----------------------------------
Falsifying example: test_netcdf_roundtrip(
    tmp_path=PosixPath('/tmp/pytest-of-vsts/pytest-0/test_netcdf_roundtrip0'), 
    data=data(...), 
    arr=array([293], dtype='timedelta64[Y]')
)
```

So either that's a pretty serious bug, or you should specify [the `max_period` of the timedelta dtype strategy](https://hypothesis.readthedocs.io/en/latest/numpy.html#hypothesis.extra.numpy.timedelta64_dtypes).","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,490228661