Forms Authentication Timeout

The security token in SharePoint forms authentication is issued by Security Token Service or STS. The token is valid for ten hours by default which can be a security concern. You can view or change the security token timeout value by using PowerShell and issuing the following commands:

$sts = Get-SPSecurityTokenServiceConfig

$sts.FormsTokenLifeTime //this will show you the current settings

//Update the timespan

$sts.FormsTokenLifeTime = (New-TimeSpan -minutes 20)

$sts.Update()

//Verify new timespan

$sts.FormsTokenLifeTime