Time Dimension Design from Cognos Perspective

Cognos do provide tecgniques like determinants at FM level to avoid double counting, but we cognos guys should make sure we don't reach to that level if possible. The best is to flatten the hierarchy, most of the time we face this issue in time dimension but if we can flatten by not having surrogate key for month level and only have it for day level, we will be good. Directly join month level fact with this day level surrogate key...