login/failed_user_auto_unlock is a SAP Parameter attribute which is used to control Enable automatic unlock off locked user at midnight information. This is available within R/3 SAP systems depending on the version and release level.
Below is the standard documentation available and a few details of the attributes values .
Controls the unlocking of users locked by logging on incorrectly. If the
parameter is set to 1, locks that were set due to failed password logon
attempts only apply on the same day (as the locking). If the parameter
is set to 0, the locks remain in effect.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.