<quote name="Aaron Schulz" date="2016-09-20" time="15:31:44 -0700">

How far ahead of time must entries be added?

I trust most people's best judgement here :)

But, as soon as you have an idea of when you'll do it is the best time to do it. Obviously if the task will impact others and/or require no other deploys at the same time that should be scheduled further in advance (~1 week) than something that is low-risk and will be completed in 2-3 hours.