To activate periodic checks of certificate’s expiration
Navigate to Device | Settings > Administration > Certificate Check.
In the CHECK CERTIFICATE EXPIRATION SETTINGS section, select Enable periodic certificate expiration check. This option is selected by default. When enabled, the Certificate expiration alert interval field becomes available.
To set the interval between certificate checks, in hours, enter the interval in the Certificate expiration alert interval: 1 - 168 (in hours) field. The minimum time is 1 hour, the maximum is 168 hours, and the default is 168.