I guess that max() and min() are not implementing yet fully: ``` python In [28]: diff.head() Out[28]: 0 NaT 1 00:00:00.128001 2 00:00:00.127999 3 00:00:00.128001 4 00:00:00.127999 Dtype: timedelta64[ns] In [29]: diff.max() Out[29]: 1934745001000 In [30]: diff.max().dtype Out[30]: dtype('int64') In [31]: diff[0].dtype Out[31]: dtype('timedelta64[ns]') In [32]: diff.min().dtype Out[32]: dtype('int64') ```