BUG: fixes #12405 by eliding values index by NaT in MPLPlot._get_xticks

Author: tsdlovell

pandas/tools/plotting.py

@@ -1325,6 +1325,7 @@ def _get_xticks(self, convert_period=False):
                 """
                 x = index._mpl_repr()
             elif is_datetype:
+                self.data = self.data[notnull(self.data.index)]
                 self.data = self.data.sort_index()
                 x = self.data.index._mpl_repr()
             else: