Setting Up Relative Time Categories

Some of the most commonly requested reports in any organization are period-over-period performance reports and trend analyses, how sales in the current period compare to sales from previous periods, and how last year's budget compares to projections for next year. By including the most commonly required relative time categories in your cubes, you avoid the need to recalculate them in every OLAP report.

The types of relative time categories are:

  • single-category periods, such as Same Month, Prior Quarter or Same Month, Prior Year
  • to-date periods, such as Year To-Date or Quarter To-Date
  • N-period running totals, such as a 2-week total in the previous month, or a 4-month total in the previous year

You can also create custom to-date and N-period relative time categories to span specified time ranges.

When using relative time categories, ensure that you set the Inclusion property to Always include for each level in the time dimension so that the relative dates are calculated correctly.

Default Relative Time Categories

The following relative time categories are automatically inserted into your model. However, you can delete them or replace them with custom time categories that better meet your users' OLAP reporting needs.

Tip: To replace automatically generated relative time categories with custom time categories, start with the closest built-in choice, change it to a custom relative time category and then change only those few settings needed to customize the category.
  • Current <period>
  • Last <period>
  • <Higher-level periods> To-Date (Grouped), including
    • <Higher-level periods> To-Date
    • Prior <Higher-level periods> To-Date
    • <Higher-level periods> To-Date Change (automatically calculated categories)
    • <Higher-level periods> To-Date Growth (automatically calculated categories)

The periods depend on the date levels defined in your model.

In the Cognos® Transformer Categories diagram, relative time periods appear in the category viewer as special categories, highlighted in pale green, below the other drill-down paths in the time dimension. Grouped special categories only appear in reports when the time dimension contains one or more levels higher than the current period.