Using GAM, when a new account is created a user activation e-mail with a user activation key is sent to the new user. The user activation key can be set to expire after a certain period of time (hours), for security reasons.
This property lets you set the ammount of time, in hours, the activation key is valid. After that period a new activation key must be generated. See User Activation Method Repository property property for details on this mechanism.
You can configure this property using GAM Web Backoffice.
The GAMRepositoryConfiguration Web Panel (located in GAM Example folder) is an example where this property is used in combination with User Activation Method Repository property.
The way to use it in GeneXus code (by using the GAM API) is the following:
&Repository.UserAutomaticActivateTimeOut = &UserAutomaticActivateTimeOut