reduction on cftime object arrays, datetime arrays

[dcherian]

I'm not sure reductions on datetime arrays work, at least we should test it.

[dcherian]

import xarray as xr

timeNP = xr.DataArray(xr.date_range('2009-01-01', '2012-12-31', use_cftime=False), dims=('time',), name='time')

timeCF = xr.DataArray(xr.date_range('2009-01-01', '2012-12-31', use_cftime=True), dims=('time',), name='time')

xr.set_options(use_flox=True)
timeNP.resample(time='YS').mean() # fails

[dcherian]

We can only really fix this for func="count", engine="flox" I think Xarray should convert to numeric and pass that to flox.