When you create a built-in account, you set its validity period, which is a number of days (from 1 to 365) that the built-in account is valid. When that date expires, the built-in account is no longer valid and cannot be used to authenticate.

But, you can renew the validity period for one or more built-in accounts with the click of the Renew button. There's no need to modify an account's validity period setting, unless you want to increase or decrease it.

Suppose you set the validity period of a new built-in account to 30 days. Once this period expires, the built-in account will not longer work. On day 30, you decide you want it to be valid for another 30 days. You select it from the Built-in Account list and click Renew. The built-in account is then valid for 30 more days.

Had you set it to 60 days, the renewal option would reset so that it would be valid for 60 days from the time you click Renew (regardless of how many days were left in the original 60-day period).

Tip: You're not required to renew a built-in account before the it expires. You can renew an existing built-in account at any time before or after its validity period ends.