Schedules Concept
Group, device or sensor monitoring can be paused by user intervention or by a "schedule" (e.g. "don't monitor Sundays between 4 and 8 a.m."). Using schedules, you can limit the monitoring time. PRTG comes with a number of pre-defined schedules. You can activate schedules in the Settings menu of a group, a device or a sensor by changing the "Inherit Schedules and Dependencies" entry. Schedules are also used in Reports and for Notifications.
To change the default pre-defined schedules or to add your own schedule, enter the account settings menu (via "Setup | Schedules").
See Account Settings - Schedules for more details.