How to properly add hours to a pandas.tseries.index.DatetimeIndex?
You can use pd.DateOffset:
test[1].index + pd.DateOffset(hours=16)pd.DateOffset accepts the same keyword arguments as dateutil.relativedelta.
The problem you encountered was due to this bug which has been fixed in Pandas version 0.14.1:
In [242]: pd.to_timedelta(16, unit='h')Out[242]: numpy.timedelta64(16,'ns')If you upgrade, your original code should work.