Great Scott!  Did you forget to send stats to a client and they want to see a prior month?  Or maybe you're just interested in doing some analysis on what the market was doing last summer.  Whatever the case, you can use several different dashboards to do just that.  An upside down arrow next to a value on any dashboard indicates that value is a filter that can be changed.  Just click on the triangle or the text to the left of it to change it.  The metrics and/or charts will all update accordingly.