At the Client level of the Reports tab you will be able to see the performance of a selected client's campaigns for 4 different time periods:
Last 7 days
Last 30 days
The heat map displays the percent deviation of your campaign's performance for whatever time frame you select.
To the right of the heat map there is a chart comparing your selected time frame to a 3 month trend graph for various metrics.
You can utilize the data within these intuitive charts to fine-tune and optimize the performance of your client's campaigns.