Fix plotting with datetime.date index values

pandas/core/frame.py

@@ -3828,7 +3828,7 @@ def plot(self, subplots=False, sharex=True, sharey=False, use_index=True,
 
         if kind == 'line':
             if use_index:
-                if self.index.is_numeric() or self.index.is_datetime():
+                if self.index.is_numeric() or self.index.is_datetype():
                     """
                     Matplotlib supports numeric values or datetime objects as
                     xaxis values. Taking LBYL approach here, by the time

pandas/core/index.py

@@ -1,6 +1,6 @@
 # pylint: disable=E1101,E1103,W0232
 
-from datetime import time, datetime
+from datetime import time, datetime, date
 from itertools import izip
 
 import numpy as np
@@ -145,9 +145,9 @@ def is_monotonic(self):
     def is_numeric(self):
         return issubclass(self.dtype.type, np.number)
 
-    def is_datetime(self):
+    def is_datetype(self):
         for key in self.values:
-            if not isinstance(key, datetime):
+            if not isinstance(key, (datetime, date)):
                 return False
         return True
 

pandas/core/series.py

@@ -2076,7 +2076,7 @@ def plot(self, label=None, kind='line', use_index=True, rot=30, ax=None,
 
         if kind == 'line':
             if use_index:
-                if self.index.is_numeric() or self.index.is_datetime():
+                if self.index.is_numeric() or self.index.is_datetype():
                     """
                     Matplotlib supports numeric values or datetime objects as
                     xaxis values. Taking LBYL approach here, by the time