Date dimensions are in high demand. Nearly every warehouse and data mart has at least one date dimension. They are extremely useful in Cognos reporting – end users frequently want to analyze data by year, quarter, month, etc.
However, there are some things that are difficult to do with a “standard” date dimension. For example, calculating period-to-date in a relational data source, or setting a report to always default to the current quarter both take more effort than they should to implement in Cognos (and both require Report Studio to accomplish). Read more