Many of your reports contain historical data so you can view trending information over time or even compare data to previous periods.
To change the time period of the report you can use the date selection tools on the report itself.
Click the date selection tool and choose from either one of the predefined date periods or select a custom date range using the calendar tool. This will change the data in the report to only show values from the date period selected.
Other reports may have pre-defined date selection options as shown below. In this instance, simply click the date range you wish from one of the pre-defined values.
Naturally, you can now save the report and it will remember the values you have chosen for next time.