With the Block periods button, you can open a dialogue box where you can completely block certain time periods during the week - in addition to limiting the computer usage. The blocked time periods are shown in red; the allowed time periods are shown in green. In order to allow or block a time period, simply highlight it using the mouse. A context menu then appears next to the cursor in which you have two options: Approve period and Block period. If users try to access the Internet during the blocked periods, an information screen will appear in the browser informing them that they do not have Internet access during that period.