There appears to be either a typo (`min` instead of `np.nanmin`) or a missing import in the new `_datetime_nanmin` function. Specifically, line 363: `array = min(array, skipna=True)` Always results in: `TypeError: 'skipna' is an invalid keyword argument for min()` Permalink: https://github.com/xarray-contrib/flox/blob/4f6164f74a657d95f795c374e31e91a7e7643e9f/flox/xrutils.py#L363C5-L363C36