This issue is connected with the fact that the pivot grid control is meant for displaying summarized and grouped data. This means that each cell can represent several rows in a corresponding data source. This behavior is well explained in the Information Presentation Basics help topic. Pivot grid provides several builds in summary calculation methods, Sum, Average, Count, Min, Max .... By default, all values are summarized. The String and DateTime types do not support arithmetic addition, and only the "0" sign is shown instead of summary values. There is an easy solution to this problem. It is only necessary to set the PivotGridFieldBase.SummaryType property of the corresponding field to Min or Max. In this case, the minimum or maximum corresponding value is displayed. In some situations, it is necessary to perform operations that are not allowed by default. E.g. Convert data from one format to another before summarizing. In this case, it is necessary to set the PivotGridFieldBase.SummaryType property to Custom and calculate summary values manually, via the PivotGridControl.CustomSummary event.