'A convenience wrapper for datetime.timedelta that handles months and years.'

def __new__(cls, *args, **kwargs):

    y = kwargs.pop('years', 0)
    m = kwargs.pop('months', 0)
    t = timedelta.__new__(cls, *args, **kwargs)
    setattr(t, 'years', y)
    setattr(t, 'months', m)
    return t
