This read-write TimeTicks value defines how long to wait, after being set, before the loopback selected in wvLoopbackType actually activates. The dual-purpose behavior noted in its own description, that writing 0 while a loopback is pending or running forces an immediate stop, gives an admin a single control point to both schedule and abort loopback tests. For example, an admin sets wvLoopbackStartTime to 6000 (60 seconds) to allow time to end a management session before the loopback interrupts the link, then later writes 0 to cancel that test early if the link is unexpectedly needed.