When running dashboards in CA Performance Mangement you can choose from a set of fixed timeframes or choose a custom timeframe
To filter data based on specific time periods, specify time ranges for dashboards. Changing the time range is useful for troubleshooting performance issues. For example, you can change the time range to show data from the last seven days. In this case, the time range helps you to determine whether an issue is occurring regularly.
You can select a precise time range for the performance data shown in the current dashboard. Use the time period selectors in the upper right corner of the dashboard page to select the day, the start time, and the end time. When you change the time range for a dashboard, the change applies to all dashboards in that window. To compare content in different time ranges, open the dashboard in multiple browser windows or modify specific views to show a fixed custom time range.