html_url,issue_url,id,node_id,user,created_at,updated_at,author_association,body,reactions,performed_via_github_app,issue https://github.com/pydata/xarray/issues/1143#issuecomment-417337306,https://api.github.com/repos/pydata/xarray/issues/1143,417337306,MDEyOklzc3VlQ29tbWVudDQxNzMzNzMwNg==,12130884,2018-08-30T14:21:55Z,2018-08-30T14:21:55Z,NONE,"Pardon me for extending this discussion. I encountered the same problem when calculating timedelta in a dataframe. It even ended with an error when I tried to call the days attribute. I am using Numpy 1.6.1 AttributeError: 'Series' object has no attribute 'days' Problem df_trans['DELTA'] = df_trans['DATE2'] - df_trans['DATE1'] print df_trans['DELTA'].dtype >>timedelta64[ns] print df_trans['DELTA'] >> 0 8 days, 00:00:00 >> 1 15 days, 00:00:00 >> 2 5 days, 00:00:00 df_trans['DELTA'] = df_trans['DELTA'].astype('timedelta64[D]') print df_trans['DELTA'].dtype >> Name: DELTA, dtype: timedelta64[D] print df_trans['DELTA'] >> 0 8 days, 00:00:00 >> 1 15 days, 00:00:00 >> 2 5 days, 00:00:00 >>Nothing changed at all print df_trans['DELTA'].days >> AttributeError: 'Series' object has no attribute 'days' I get rid of the problem by putting it in to a list for the conversion. Ss_timedelta = df_trans['DATE2'] - df_trans['DATE1'] ls_timedelta = Ss_timedelta.values.astype('timedelta64[D]').tolist() for i in range(0, len(ls_timedelta)): ls_timedelta[i] = ls_timedelta[i].days / 1000 df_trans['HOLDDAYS'] = pd.Series(ls_timedelta) ","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,192325490