fix and rebase

Author: reidy-p

pandas/core/indexes/datetimes.py

@@ -615,6 +615,8 @@ def _simple_new(cls, values, name=None, freq=None, tz=None,
         if not is_datetime64_dtype(values):
             values = _ensure_int64(values).view(_NS_DTYPE)
 
+        values = getattr(values, 'values', values)
+
         assert isinstance(values, np.ndarray), "values is not an np.ndarray"
         assert is_datetime64_dtype(values)