Easy way to convert Julian calendar to standard with Python xarray?

Question

I'm new to Python and I'm using xarray. My netcdf file contains data with time given in 'days since 0001-01-01 00:00:00', calendar type is Julian. Does anybody know an easy way to convert the time to standard calendar?

Thanks in advance :)

xarray.Dataset.convert_calendar() 

didn't work for me

datetime.datetime.strptime(Dataset.time, "%Y %m %d %H %M")

and similar also did not work.

Answer 1

You can convert Julian dates to a standard calendar (usually Gregorian) in xarray using cftime library. Here's a minimal example:

1. Install cftime: pip install cftime
2. Convert time coordinates.

import xarray as xr
import cftime

# Load your dataset
ds = xr.open_dataset('your_file.nc')

# Convert Julian to standard calendar (e.g., Gregorian)
ds['time'] = xr.coding.times.decode_cf_datetime(ds['time'], calendar='gregorian')

# Now ds['time'] is in Gregorian

Note: Replace 'your_file.nc' with your NetCDF file path.

Hope that helps!