Use conda-forge netcdftime wherever netcdf4 was tested

.travis.yml

@@ -45,8 +45,6 @@ matrix:
     env: CONDA_ENV=py36-rasterio1.0alpha
   - python: 3.6
     env: CONDA_ENV=py36-zarr-dev
-  - python: 3.6
-    env: CONDA_ENV=py36-netcdftime-dev
   - python: 3.5
     env: CONDA_ENV=docs
   allow_failures:
@@ -75,8 +73,6 @@ matrix:
     env: CONDA_ENV=py36-rasterio1.0alpha
   - python: 3.6
     env: CONDA_ENV=py36-zarr-dev
-  - python: 3.6
-    env: CONDA_ENV=py36-netcdftime-dev
 
 before_install:
   - if [[ "$TRAVIS_PYTHON_VERSION" == "2.7" ]]; then

ci/requirements-py27-cdat+iris+pynio.yml

@@ -11,6 +11,7 @@ dependencies:
   - h5netcdf
   - matplotlib
   - netcdf4
+  - netcdftime
   - numpy
   - pandas
   - pathlib2

ci/requirements-py27-windows.yml

@@ -9,6 +9,7 @@ dependencies:
   - h5netcdf
   - matplotlib
   - netcdf4
+  - netcdftime
   - pathlib2
   - pytest
   - flake8

ci/requirements-py35.yml

@@ -9,6 +9,7 @@ dependencies:
   - h5netcdf
   - matplotlib
   - netcdf4
+  - netcdftime
   - pytest
   - flake8
   - numpy

ci/requirements-py36-bottleneck-dev.yml

@@ -9,6 +9,7 @@ dependencies:
   - h5netcdf
   - matplotlib
   - netcdf4
+  - netcdftime
   - pytest
   - flake8
   - numpy

ci/requirements-py36-condaforge-rc.yml

@@ -10,6 +10,7 @@ dependencies:
   - h5netcdf
   - matplotlib
   - netcdf4
+  - netcdftime
   - pytest
   - flake8
   - numpy

ci/requirements-py36-dask-dev.yml

@@ -7,6 +7,7 @@ dependencies:
   - h5netcdf
   - matplotlib
   - netcdf4
+  - netcdftime
   - pytest
   - flake8
   - numpy

ci/requirements-py36-netcdf4-dev.yml

@@ -19,3 +19,4 @@ dependencies:
     - coveralls
     - pytest-cov
     - git+https://github.com/Unidata/netcdf4-python.git
+    - git+https://github.com/Unidata/netcdftime.git

ci/requirements-py36-pandas-dev.yml

@@ -10,6 +10,7 @@ dependencies:
   - h5netcdf
   - matplotlib
   - netcdf4
+  - netcdftime
   - pytest
   - flake8
   - numpy

ci/requirements-py36-pynio-dev.yml

@@ -10,6 +10,7 @@ dependencies:
   - h5netcdf
   - matplotlib
   - netcdf4
+  - netcdftime
   - pynio=dev
   - pytest
   - numpy

ci/requirements-py36-rasterio1.0alpha.yml

@@ -10,6 +10,7 @@ dependencies:
   - h5netcdf
   - matplotlib
   - netcdf4
+  - netcdftime
   - pytest
   - numpy
   - pandas

ci/requirements-py36-windows.yml

@@ -9,6 +9,7 @@ dependencies:
   - h5netcdf
   - matplotlib
   - netcdf4
+  - netcdftime
   - pytest
   - numpy
   - pandas

ci/requirements-py36-zarr-dev.yml

@@ -14,6 +14,7 @@ dependencies:
   - seaborn
   - toolz
   - bottleneck
+  - netcdftime
   - pip:
     - coveralls
     - pytest-cov

ci/requirements-py36.yml

@@ -9,6 +9,7 @@ dependencies:
   - h5netcdf
   - matplotlib
   - netcdf4
+  - netcdftime
   - pytest
   - flake8
   - numpy

doc/installing.rst

@@ -25,7 +25,7 @@ For netCDF and IO
 - `pynio <https://www.pyngl.ucar.edu/Nio.shtml>`__: for reading GRIB and other
   geoscience specific file formats
 - `zarr <http://zarr.readthedocs.io/>`__: for chunked, compressed, N-dimensional arrays.
-- `netcdftime <https://github.com/Unidata/netcdftime>`__: recommended if you
+- `netcdftime <https://unidata.github.io/netcdftime>`__: recommended if you
   want to encode/decode datetimes for non-standard calendars.
 
 For accelerating xarray

doc/time-series.rst

@@ -47,6 +47,17 @@ attribute like ``'days since 2000-01-01'``).
 
 .. _CF conventions: http://cfconventions.org
 
+.. note::
+
+   When decoding/encoding datetimes for non-standard calendars or for dates
+   before year 1678 or after year 2262, xarray uses the `netcdftime`_ library.
+   ``netcdftime`` was previously packaged with the ``netcdf4-python`` package but
+   is now diestributed separately. ``netcdftime`` is an
+   :ref:`optional dependency<installing>` of xarray.
+
+.. _netcdftime: https://unidata.github.io/netcdftime
+
+
 You can manual decode arrays in this form by passing a dataset to
 :py:func:`~xarray.decode_cf`:
 

doc/whats-new.rst

@@ -95,15 +95,19 @@ Enhancements
   By `Stephan Hoyer <https://github.com/shoyer>`_.
 - Fix ``axis`` keyword ignored when applying ``np.squeeze`` to ``DataArray`` (:issue:`1487`).
   By `Florian Pinault <https://github.com/floriankrb>`_.
-- Add ``netcdftime`` as an optional dependency of xarray. This allows for
+- ``netcdf4-python`` has moved the its time handling in the ``netcdftime`` module to
+  a standalone package (`netcdftime`_). As such, xarray now considers `netcdftime`_
+  an optional dependency. One benefit of this change is that it allows for
   encoding/decoding of datetimes with non-standard calendars without the
-  netCDF4 dependency (:issue:`1084`).
+  ``netcdf4-python`` dependency (:issue:`1084`).
   By `Joe Hamman <https://github.com/jhamman>`_.
 
 .. _Zarr: http://zarr.readthedocs.io/
 
 .. _Iris: http://scitools.org.uk/iris
 
+.. _netcdftime: https://unidata.github.io/netcdftime
+
 **New functions/methods**
 
 - New :py:meth:`~xarray.DataArray.rank` on arrays and datasets. Requires