Fix netcdf with time coordinate containing cftime (#403)

src/earthkit/data/readers/netcdf/coords.py

@@ -19,7 +19,14 @@
 
 
 def as_datetime(self, time):
-    return datetime.datetime.strptime(str(time)[:19], "%Y-%m-%dT%H:%M:%S")
+    if isinstance(time, datetime.datetime):
+        return time
+    elif hasattr(time, "isoformat"):
+        return datetime.datetime.fromisoformat(time.isoformat())
+    elif hasattr(time, "to_datetime"):
+        return time.to_datetime()
+    else:
+        return datetime.datetime.strptime(str(time)[:19], "%Y-%m-%dT%H:%M:%S")
 
 
 def as_level(self, level):

src/earthkit/data/readers/netcdf/fieldlist.py

@@ -100,7 +100,12 @@ def _skip_attr(v, attr_name):
                 use = True
 
             # Of course, not every one sets the standard_name
-            if standard_name in ["time", "forecast_reference_time"] or long_name in ["time"] or axis == "T":
+            if (
+                standard_name in ["time", "forecast_reference_time"]
+                or long_name in ["time"]
+                or coord_name.lower() in ["time"]
+                or axis == "T"
+            ):
                 # we might not be able to convert time to datetime
                 try:
                     coordinates.append(TimeCoordinate(c, coord in info))
@@ -200,7 +205,8 @@ def to_xarray_multi_from_paths(cls, paths, **kwargs):
         )
 
     def to_netcdf(self, *args, **kwargs):
-        """Save the data to a netCDF file.
+        """
+        Save the data to a netCDF file.
 
         Parameters
         ----------

tests/netcdf/test_netcdf_fieldlist.py

@@ -12,6 +12,7 @@
 import numpy as np
 
 import earthkit.data
+from earthkit.data.testing import earthkit_remote_test_data_file
 
 
 def test_netcdf_fieldlist_string_coord():
@@ -60,6 +61,17 @@ def test_netcdf_fieldlist_bounds():
     assert len(ds) == 2
 
 
+def test_netcdf_fieldlist_ctime():
+    ds = earthkit.data.from_source(
+        "url",
+        earthkit_remote_test_data_file("test-data", "zgrid_rhgmet_metop_200701_R_2305_0010.nc"),
+    )
+
+    assert len(ds) == 1506
+    assert ds[0].metadata("valid_datetime") == "2007-01-16T00:00:00"
+    assert ds[5].metadata("valid_datetime") == "2007-01-16T00:00:00"
+
+
 if __name__ == "__main__":
     from earthkit.data.testing import main