This option defines the access time restriction for the user account.
When you enable this option, you must add some access time rules, otherwise, this user can't login any more.
Enable access schedule
Activate or deactivate the restriction.
Add Access Schedule
Add "Access Time Schedule" for this user. This user can log in at your specified time.
Edit your "Time Schedule."
Delete the selected "Time Schedule."
Delete all "Time Schedule." This user can never log in again unless you disable "Access Time Schedule."