This object specifies, in nanoseconds in 8ns steps over a range of -5,000,000 to 5,000,000, an external delay compensation applied to an input Time Of Day port. Admins use it to offset known cable or equipment propagation delay so the received time-of-day value reflects the true time rather than a delayed copy. For example, if a long fiber run to the TOD source introduces a measured delay, the admin sets f3TimeOfDayPortDelayCompensation to cancel it out and keep the port's reported time accurate.