id,node_id,number,title,user,state,locked,assignee,milestone,comments,created_at,updated_at,closed_at,author_association,active_lock_reason,draft,pull_request,body,reactions,performed_via_github_app,state_reason,repo,type 822987300,MDU6SXNzdWU4MjI5ODczMDA=,5001,.min() doesn't work on np.datetime64 with a chunked Dataset,49512274,open,0,,,2,2021-03-05T11:12:19Z,2022-05-01T16:11:48Z,,NONE,,,," Hi all, if a xr.Dataset is chunked, i cannot do ds.time.min(), i get an error : `ufunc 'add' cannot use operands with types dtype('Output of xr.show_versions() INSTALLED VERSIONS ------------------ commit: None python: 3.7.9 (default, Aug 31 2020, 12:42:55) [GCC 7.3.0] python-bits: 64 OS: Linux OS-release: 4.15.0-133-generic machine: x86_64 processor: x86_64 byteorder: little LC_ALL: None LANG: fr_FR.UTF-8 LOCALE: fr_FR.UTF-8 libhdf5: 1.12.0 libnetcdf: 4.7.4 xarray: 0.16.2 pandas: 1.2.1 numpy: 1.19.5 scipy: 1.6.0 netCDF4: 1.5.5.1 pydap: None h5netcdf: None h5py: None Nio: None zarr: 2.6.1 cftime: 1.3.1 nc_time_axis: None PseudoNetCDF: None rasterio: None cfgrib: None iris: None bottleneck: None dask: 2021.01.1 distributed: 2021.01.1 matplotlib: 3.3.4 cartopy: None seaborn: None numbagg: None pint: 0.16.1 setuptools: 52.0.0.post20210125 pip: 20.3.3 conda: None pytest: 6.2.2 IPython: 7.20.0 sphinx: 3.5.0 ","{""url"": ""https://api.github.com/repos/pydata/xarray/issues/5001/reactions"", ""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,,13221727,issue