matplotlib
diff --git a/‎lib/matplotlib/tests/test_datetime.py
Lines changed: 35 additions & 3 deletions b/‎lib/matplotlib/tests/test_datetime.py
Lines changed: 35 additions & 3 deletions
@@ -343,11 +343,43 @@ def test_hist2d(self):
         fig, ax = plt.subplots()
         ax.hist2d(...)
 
-    @pytest.mark.xfail(reason="Test for hlines not written yet")
     @mpl.style.context("default")
     def test_hlines(self):
-        fig, ax = plt.subplots()
-        ax.hlines(...)
+        mpl.rcParams["date.converter"] = 'concise'
+        fig, axs = plt.subplots(2, 4, layout='constrained')
+        dateStrs = ['2023-03-08',
+                    '2023-04-09',
+                    '2023-05-13',
+                    '2023-07-28',
+                    '2023-12-24']
+        dates = [datetime.datetime(2023, m*2, 10) for m in range(1, 6)]
+        date_start = [datetime.datetime(2023, 6, d) for d in range(5, 30, 5)]
+        date_end = [datetime.datetime(2023, 7, d) for d in range(5, 30, 5)]
+        npDates = [np.datetime64(s) for s in dateStrs]
+        axs[0, 0].hlines(y=dates,
+                         xmin=[0.1, 0.2, 0.3, 0.4, 0.5],
+                         xmax=[0.5, 0.6, 0.7, 0.8, 0.9])
+        axs[0, 1].hlines(dates,
+                         xmin=datetime.datetime(2020, 5, 10),
+                         xmax=datetime.datetime(2020, 5, 31))
+        axs[0, 2].hlines(dates,
+                         xmin=date_start,
+                         xmax=date_end)
+        axs[0, 3].hlines(dates,
+                         xmin=0.45,
+                         xmax=0.65)
+        axs[1, 0].hlines(y=npDates,
+                         xmin=[0.5, 0.6, 0.7, 0.8, 0.9],
+                         xmax=[0.1, 0.2, 0.3, 0.4, 0.5])
+        axs[1, 2].hlines(y=npDates,
+                         xmin=date_start,
+                         xmax=date_end)
+        axs[1, 1].hlines(npDates,
+                         xmin=datetime.datetime(2020, 5, 10),
+                         xmax=datetime.datetime(2020, 5, 31))
+        axs[1, 3].hlines(npDates,
+                         xmin=0.45,
+                         xmax=0.65)
 
     @pytest.mark.xfail(reason="Test for imshow not written yet")
     @mpl.style.context("default")