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
1128759050,I_kwDOAMm_X85DR38K,6259,Be able to override calendar in `open_dataset`/`open_mfdataset`/etc OR include another calendar name,3487237,open,0,,,6,2022-02-09T16:25:24Z,2024-02-12T15:28:15Z,,NONE,,,,"### Is your feature request related to a problem?

I think there was a version of ROMS in which the calendar was written as ""gregorian_proleptic"" instead of ""proleptic_gregorian"". Only the latter is checked for by xarray for valid calendar names. This unfortunately keeps coming up when I need to deal with model output from such ROMS simulations. I personally am using catalogs to access model output (e.g., intake, stac), making it so I need to be able to provide flags to the `open_*` command in order to be able to read in the model output from the catalog (i.e. rather than being able to run a command afterward to, say, overwrite the calendar with the correct name). 

### Describe the solution you'd like

I would like to either:
1. include ""gregorian_proleptic"" on the known list of calendars, or
2. be able to provide a keyword argument to the ""open_*"" commands to declare the calendar I want to use, overwriting what is in the file metadata.

### Describe alternatives you've considered

I have used `decode_times=False` in this situation before and then sort of forced the datetimes into submission, but that solution won't work with a catalog setup in which all the necessary keywords to open the file(s) need to be in catalog entry.

### Additional context

This code demonstrates the issue:
```
import xarray as xr
url = 'https://www.ncei.noaa.gov/thredds/dodsC/model-cbofs-files/2020/02/nos.cbofs.fields.n006.20200208.t18z.nc'
ds = xr.open_dataset(url, drop_variables=['dstart'])
```","{""url"": ""https://api.github.com/repos/pydata/xarray/issues/6259/reactions"", ""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,,13221727,issue