matplotlib · timhoffm · Mar 3, 2025 · Mar 2, 2025
diff --git a/doc/api/axes_api.rst b/doc/api/axes_api.rst
@@ -54,7 +54,6 @@ Basic
    Axes.errorbar
    Axes.scatter
 
-   Axes.plot_date
    Axes.step
 
    Axes.loglog

diff --git a/doc/api/next_api_changes/removals/29697-REC.rst b/doc/api/next_api_changes/removals/29697-REC.rst
@@ -0,0 +1,10 @@
+``plot_date``
+~~~~~~~~~~~~~
+
+Use of ``plot_date`` has been discouraged since Matplotlib 3.5 and deprecated
+since 3.9. The ``plot_date`` function has now been removed.
+
+- ``datetime``-like data should directly be plotted using `~.Axes.plot`.
+-  If you need to plot plain numeric data as :ref:`date-format` or need to set
+   a timezone, call ``ax.xaxis.axis_date`` / ``ax.yaxis.axis_date`` before
+   `~.Axes.plot`. See `.Axis.axis_date`.
diff --git a/doc/api/prev_api_changes/api_changes_1.4.x.rst b/doc/api/prev_api_changes/api_changes_1.4.x.rst
@@ -139,7 +139,7 @@ Code changes
   ``matplotlib.testing.image_util.autocontrast``. These will be removed
   completely in v1.5.0.
 
-* The ``fmt`` argument of :meth:`~matplotlib.axes.Axes.plot_date` has been
+* The ``fmt`` argument of ``Axes.plot_date`` has been
   changed from ``bo`` to just ``o``, so color cycling can happen by default.
 
 * Removed the class ``FigureManagerQTAgg`` and deprecated

diff --git a/doc/api/prev_api_changes/api_changes_3.5.0/deprecations.rst b/doc/api/prev_api_changes/api_changes_3.5.0/deprecations.rst
@@ -47,7 +47,7 @@ type. See their documentation for the types they expect.
 Discouraged: ``plot_date``
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-The use of `~.Axes.plot_date` is discouraged. This method exists for historic
+The use of ``plot_date`` is discouraged. This method exists for historic
 reasons and may be deprecated in the future.
 
 - ``datetime``-like data should directly be plotted using `~.Axes.plot`.

diff --git a/doc/api/prev_api_changes/api_changes_3.9.0/deprecations.rst b/doc/api/prev_api_changes/api_changes_3.9.0/deprecations.rst
@@ -4,7 +4,7 @@ Deprecations
 ``plot_date``
 ^^^^^^^^^^^^^
 
-Use of `~.Axes.plot_date` has been discouraged since Matplotlib 3.5 and the function is
+Use of ``plot_date`` has been discouraged since Matplotlib 3.5 and the function is
 now formally deprecated.
 
 - ``datetime``-like data should directly be plotted using `~.Axes.plot`.

diff --git a/doc/api/pyplot_summary.rst b/doc/api/pyplot_summary.rst
@@ -51,7 +51,6 @@ Basic
    plot
    errorbar
    scatter
-   plot_date
    step
    loglog
    semilogx

diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -1778,87 +1778,6 @@ def plot(self, *args, scalex=True, scaley=True, data=None, **kwargs):
             self._request_autoscale_view("y")
         return lines
 
-    @_api.deprecated("3.9", alternative="plot")
-    @_preprocess_data(replace_names=["x", "y"], label_namer="y")
-    @_docstring.interpd
-    def plot_date(self, x, y, fmt='o', tz=None, xdate=True, ydate=False,
-                  **kwargs):
-        """
-        Plot coercing the axis to treat floats as dates.
-
-        .. deprecated:: 3.9
-
-            This method exists for historic reasons and will be removed in version 3.11.
-
-            - ``datetime``-like data should directly be plotted using
-              `~.Axes.plot`.
-            -  If you need to plot plain numeric data as :ref:`date-format` or
-               need to set a timezone, call ``ax.xaxis.axis_date`` /
-               ``ax.yaxis.axis_date`` before `~.Axes.plot`. See
-               `.Axis.axis_date`.
-
-        Similar to `.plot`, this plots *y* vs. *x* as lines or markers.
-        However, the axis labels are formatted as dates depending on *xdate*
-        and *ydate*.  Note that `.plot` will work with `datetime` and
-        `numpy.datetime64` objects without resorting to this method.
-
-        Parameters
-        ----------
-        x, y : array-like
-            The coordinates of the data points. If *xdate* or *ydate* is
-            *True*, the respective values *x* or *y* are interpreted as
-            :ref:`Matplotlib dates <date-format>`.
-
-        fmt : str, optional
-            The plot format string. For details, see the corresponding
-            parameter in `.plot`.
-
-        tz : timezone string or `datetime.tzinfo`, default: :rc:`timezone`
-            The time zone to use in labeling dates.
-
-        xdate : bool, default: True
-            If *True*, the *x*-axis will be interpreted as Matplotlib dates.
-
-        ydate : bool, default: False
-            If *True*, the *y*-axis will be interpreted as Matplotlib dates.
-
-        Returns
-        -------
-        list of `.Line2D`
-            Objects representing the plotted data.
-
-        Other Parameters
-        ----------------
-        data : indexable object, optional
-            DATA_PARAMETER_PLACEHOLDER
-        **kwargs
-            Keyword arguments control the `.Line2D` properties:
-
-            %(Line2D:kwdoc)s
-
-        See Also
-        --------
-        matplotlib.dates : Helper functions on dates.
-        matplotlib.dates.date2num : Convert dates to num.
-        matplotlib.dates.num2date : Convert num to dates.
-        matplotlib.dates.drange : Create an equally spaced sequence of dates.
-
-        Notes
-        -----
-        If you are using custom date tickers and formatters, it may be
-        necessary to set the formatters/locators after the call to
-        `.plot_date`. `.plot_date` will set the default tick locator to
-        `.AutoDateLocator` (if the tick locator is not already set to a
-        `.DateLocator` instance) and the default tick formatter to
-        `.AutoDateFormatter` (if the tick formatter is not already set to a
-        `.DateFormatter` instance).
-        """
-        if xdate:
-            self.xaxis_date(tz)
-        if ydate:
-            self.yaxis_date(tz)
-        return self.plot(x, y, fmt, **kwargs)
-
     # @_preprocess_data() # let 'plot' do the unpacking..
     @_docstring.interpd
     def loglog(self, *args, **kwargs):

diff --git a/lib/matplotlib/axes/_axes.pyi b/lib/matplotlib/axes/_axes.pyi
@@ -200,18 +200,6 @@ class Axes(_AxesBase):
         data=...,
         **kwargs
     ) -> list[Line2D]: ...
-    def plot_date(
-        self,
-        x: ArrayLike,
-        y: ArrayLike,
-        fmt: str = ...,
-        tz: str | datetime.tzinfo | None = ...,
-        xdate: bool = ...,
-        ydate: bool = ...,
-        *,
-        data=...,
-        **kwargs
-    ) -> list[Line2D]: ...
     def loglog(self, *args, **kwargs) -> list[Line2D]: ...
     def semilogx(self, *args, **kwargs) -> list[Line2D]: ...
     def semilogy(self, *args, **kwargs) -> list[Line2D]: ...

diff --git a/lib/matplotlib/pyplot.py b/lib/matplotlib/pyplot.py
@@ -86,7 +86,6 @@
 
 if TYPE_CHECKING:
     from collections.abc import Callable, Hashable, Iterable, Sequence
-    import datetime
     import pathlib
     import os
     from typing import Any, BinaryIO, Literal, TypeVar
@@ -3834,31 +3833,6 @@ def plot(
     )
 
 
-# Autogenerated by boilerplate.py.  Do not edit as changes will be lost.
-@_copy_docstring_and_deprecators(Axes.plot_date)
-def plot_date(
-    x: ArrayLike,
-    y: ArrayLike,
-    fmt: str = "o",
-    tz: str | datetime.tzinfo | None = None,
-    xdate: bool = True,
-    ydate: bool = False,
-    *,
-    data=None,
-    **kwargs,
-) -> list[Line2D]:
-    return gca().plot_date(
-        x,
-        y,
-        fmt=fmt,
-        tz=tz,
-        xdate=xdate,
-        ydate=ydate,
-        **({"data": data} if data is not None else {}),
-        **kwargs,
-    )
-
-
 # Autogenerated by boilerplate.py.  Do not edit as changes will be lost.
 @_copy_docstring_and_deprecators(Axes.psd)
 def psd(

diff --git a/lib/matplotlib/tests/baseline_images/test_axes/date_timezone_x.png b/lib/matplotlib/tests/baseline_images/test_axes/date_timezone_x.png
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/date_timezone_x_and_y.png b/lib/matplotlib/tests/baseline_images/test_axes/date_timezone_x_and_y.png
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/date_timezone_y.png b/lib/matplotlib/tests/baseline_images/test_axes/date_timezone_y.png
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/single_date.png b/lib/matplotlib/tests/baseline_images/test_axes/single_date.png
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -895,22 +895,6 @@ def test_single_point():
     ax2.plot('b', 'b', 'o', data=data)
 
 
-@image_comparison(['single_date.png'], style='mpl20')
-def test_single_date():
-
-    # use former defaults to match existing baseline image
-    plt.rcParams['axes.formatter.limits'] = -7, 7
-    dt = mdates.date2num(np.datetime64('0000-12-31'))
-
-    time1 = [721964.0]
-    data1 = [-65.54]
-
-    fig, ax = plt.subplots(2, 1)
-    with pytest.warns(mpl.MatplotlibDeprecationWarning):
-        ax[0].plot_date(time1 + dt, data1, 'o', color='r')
-    ax[1].plot(time1, data1, 'o', color='r')
-
-
 @check_figures_equal(extensions=["png"])
 def test_shaped_data(fig_test, fig_ref):
     row = np.arange(10).reshape((1, -1))
@@ -7299,63 +7283,6 @@ def test_bar_uint8():
         assert patch.xy[0] == x
 
 
-@image_comparison(['date_timezone_x.png'], tol=1.0)
-def test_date_timezone_x():
-    # Tests issue 5575
-    time_index = [datetime.datetime(2016, 2, 22, hour=x,
-                                    tzinfo=dateutil.tz.gettz('Canada/Eastern'))
-                  for x in range(3)]
-
-    # Same Timezone
-    plt.figure(figsize=(20, 12))
-    plt.subplot(2, 1, 1)
-    with pytest.warns(mpl.MatplotlibDeprecationWarning):
-        plt.plot_date(time_index, [3] * 3, tz='Canada/Eastern')
-
-    # Different Timezone
-    plt.subplot(2, 1, 2)
-    with pytest.warns(mpl.MatplotlibDeprecationWarning):
-        plt.plot_date(time_index, [3] * 3, tz='UTC')
-
-
-@image_comparison(['date_timezone_y.png'])
-def test_date_timezone_y():
-    # Tests issue 5575
-    time_index = [datetime.datetime(2016, 2, 22, hour=x,
-                                    tzinfo=dateutil.tz.gettz('Canada/Eastern'))
-                  for x in range(3)]
-
-    # Same Timezone
-    plt.figure(figsize=(20, 12))
-    plt.subplot(2, 1, 1)
-    with pytest.warns(mpl.MatplotlibDeprecationWarning):
-        plt.plot_date([3] * 3, time_index, tz='Canada/Eastern', xdate=False, ydate=True)
-
-    # Different Timezone
-    plt.subplot(2, 1, 2)
-    with pytest.warns(mpl.MatplotlibDeprecationWarning):
-        plt.plot_date([3] * 3, time_index, tz='UTC', xdate=False, ydate=True)
-
-
-@image_comparison(['date_timezone_x_and_y.png'], tol=1.0)
-def test_date_timezone_x_and_y():
-    # Tests issue 5575
-    UTC = datetime.timezone.utc
-    time_index = [datetime.datetime(2016, 2, 22, hour=x, tzinfo=UTC)
-                  for x in range(3)]
-
-    # Same Timezone
-    plt.figure(figsize=(20, 12))
-    plt.subplot(2, 1, 1)
-    with pytest.warns(mpl.MatplotlibDeprecationWarning):
-        plt.plot_date(time_index, time_index, tz='UTC', ydate=True)
-
-    # Different Timezone
-    plt.subplot(2, 1, 2)
-    with pytest.warns(mpl.MatplotlibDeprecationWarning):
-        plt.plot_date(time_index, time_index, tz='US/Eastern', ydate=True)
-
-
 @image_comparison(['axisbelow.png'], remove_text=True)
 def test_axisbelow():
     # Test 'line' setting added in 6287.

diff --git a/lib/matplotlib/tests/test_datetime.py b/lib/matplotlib/tests/test_datetime.py
@@ -642,26 +642,6 @@ def test_plot(self):
         ax2.plot(range(1, N), x)
         ax3.plot(x, x)
 
-    @mpl.style.context("default")
-    def test_plot_date(self):
-        mpl.rcParams["date.converter"] = "concise"
-        range_threshold = 10
-        fig, (ax1, ax2, ax3) = plt.subplots(3, 1, layout="constrained")
-
-        x_dates = np.array(
-            [datetime.datetime(2023, 10, delta) for delta in range(1, range_threshold)]
-        )
-        y_dates = np.array(
-            [datetime.datetime(2023, 10, delta) for delta in range(1, range_threshold)]
-        )
-        x_ranges = np.array(range(1, range_threshold))
-        y_ranges = np.array(range(1, range_threshold))
-
-        with pytest.warns(mpl.MatplotlibDeprecationWarning):
-            ax1.plot_date(x_dates, y_dates)
-            ax2.plot_date(x_dates, y_ranges)
-            ax3.plot_date(x_ranges, y_dates)
-
     @pytest.mark.xfail(reason="Test for quiver not written yet")
     @mpl.style.context("default")
     def test_quiver(self):

diff --git a/lib/matplotlib/tests/test_pyplot.py b/lib/matplotlib/tests/test_pyplot.py
@@ -381,7 +381,7 @@ def extract_documented_functions(lines):
                :nosignatures:
 
                plot
-               plot_date
+               errorbar
 
         """
         functions = []

diff --git a/lib/mpl_toolkits/axes_grid1/tests/test_axes_grid1.py b/lib/mpl_toolkits/axes_grid1/tests/test_axes_grid1.py
@@ -92,8 +92,8 @@ def test_twin_axes_empty_and_removed():
 
 def test_twin_axes_both_with_units():
     host = host_subplot(111)
-    with pytest.warns(mpl.MatplotlibDeprecationWarning):
-        host.plot_date([0, 1, 2], [0, 1, 2], xdate=False, ydate=True)
+    host.yaxis.axis_date()
+    host.plot([0, 1, 2], [0, 1, 2])
     twin = host.twinx()
     twin.plot(["a", "b", "c"])
     assert host.get_yticklabels()[0].get_text() == "00:00:00"

diff --git a/tools/boilerplate.py b/tools/boilerplate.py
@@ -256,7 +256,6 @@ def boilerplate_gen():
         'phase_spectrum',
         'pie',
         'plot',
-        'plot_date',
         'psd',
         'quiver',
         'quiverkey',
-Original file line number
+Diff line change
@@ Expand Up / @@ -51,7 +51,6 @@ Basic @@
        plot
        errorbar
        scatter
-       plot_date
        step
        loglog
        semilogx
@@ Expand Down @@