The confirmation period states how long we wait after observing a failure before we start a new incident.
The recovery period states how long a monitor has to be up before we automatically mark it as recovered, and the related incident as resolved.
To change the confirmation or recovery period, go to Monitors → Select a monitor → Configure → Advanced settings and set the dropdown to your preferred period.
To better understand how this works, let's take a monitor with a 1-minute check frequency, immediate confirmation period, and 1-minute recovery period.
When this monitor observers a downtime, it will create an incident immediately, as the confirmation period is set to an immediate start. If the next check that comes after 1-minute shows the monitor as available (up and working), it will start the confirmation period countdown. This will take 60 seconds, during which 2 additional checks are performed, and both need to be valid in order for the incident to resolve automatically.
If any of the checks fails during the recovery period, the counter is reset and the monitor is waiting once more for a valid check to start the recovery period again.