This help page is for version 4.0. The latest available help is for version 5.1.
Most monitors have a Schedule button in the lower right corner of their configuration dialog. When the mouse hovers over the Schedule button, the Schedule window is shown below:
You can schedule the monitor to run using a time-based period, on a daily, weekly or monthly schedule.
Advanced Options for most monitors will also let you specify a time during the week (in 30 minute increments) when a specific monitor should not be run. This might be useful during system backup for example.