implement unique

pandas/core/indexes/datetimelike.py

@@ -212,6 +212,7 @@ def ceil(self, freq, ambiguous='raise'):
 
 class DatetimeIndexOpsMixin(DatetimeLikeArrayMixin):
     """ common ops mixin to support a unified interface datetimelike Index """
+    copy = Index.copy
 
     # DatetimeLikeArrayMixin assumes subclasses are mutable, so these are
     # properties there.  They can be made into cache_readonly for Index

pandas/core/indexes/datetimes.py

@@ -569,7 +569,10 @@ def unique(self, level=None):
             naive = type(self)(self._ndarray_values, copy=False)
         else:
             naive = self
-        result = super(DatetimeIndex, naive).unique(level=level)
+
+        if level is not None:
+            self._validate_index_level(level)
+        result = DatetimeArray.unique(self)
         return self._shallow_copy(result.values)
 
     def union(self, other):

pandas/core/indexes/timedeltas.py

@@ -614,6 +614,12 @@ def delete(self, loc):
 
         return TimedeltaIndex(new_tds, name=self.name, freq=freq)
 
+    def unique(self, level=None):
+        if level is not None:
+            self._validate_index_level(level)
+        result = TimedeltaArrayMixin.unique(self)
+        return self._shallow_copy(result.values)
+
 
 TimedeltaIndex._add_comparison_ops()
 TimedeltaIndex._add_numeric_methods()