This read-write value selects how the device recovers to a higher-priority timing source once it becomes available again after a failover, choosing manual(1), automatic(2), or timed(3). An admin sets it to control whether the device switches back to the preferred clock source automatically, waits for a timed delay, or requires manual intervention, which affects how much disruption a clock switch-back can cause. For example, an admin worried about clock-switch disruption might set this to timed(3) so the device waits out a stabilization period on the recovering source before switching back, rather than reverting immediately.