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/issues/2886#issuecomment-525418536,https://api.github.com/repos/pydata/xarray/issues/2886,525418536,MDEyOklzc3VlQ29tbWVudDUyNTQxODUzNg==,31460695,2019-08-27T18:08:07Z,2019-08-27T18:08:07Z,NONE,"@Geektrovert and @spencerkclark  - any progress on this?  It would be great to have it working in time for the CMIP6 hackathon in order to suppress all of the warning messages when opening zarr stores.  For example,  a zarr store using `cftime.DatetimeGregorian` (e.g., cftime.DatetimeGregorian(2349, 12, 16, 12, 0, 0, 0, 4, 350)) will always generate the warning:
```
/usr/local/python/anaconda3/envs/pangeoJun2019/lib/python3.6/site-packages/xarray/coding/times.py:465: SerializationWarning: Unable to decode time axis into full numpy.datetime64 objects, continuing using cftime.datetime objects instead, reason: dates out of range
  dtype = _decode_cf_datetime_dtype(data, units, calendar, self.use_cftime)
/usr/local/python/anaconda3/envs/pangeoJun2019/lib/python3.6/site-packages/xarray/coding/times.py:465: SerializationWarning: Unable to decode time axis into full numpy.datetime64 objects, continuing using cftime.datetime objects instead, reason: dates out of range
  dtype = _decode_cf_datetime_dtype(data, units, calendar, self.use_cftime)
/usr/local/python/anaconda3/envs/pangeoJun2019/lib/python3.6/site-packages/numpy/core/numeric.py:538: SerializationWarning: Unable to decode time axis into full numpy.datetime64 objects, continuing using cftime.datetime objects instead, reason: dates out of range
  return array(a, dtype, copy=False, order=order)
```
For the CMIP6 collection, I always use `use_cftime=True`  in  open_mfdataset, but then when I make the zarr store and read it back in, it generates these warnings - always a distraction for anyone not used to dealing with this data","{""total_count"": 1, ""+1"": 1, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,431970156