how do you choose load monitoring time limit?

The load monitoring tool displays all flights are have a load of x% or less (with x being chosen by you) in the time-frame selected (currently, they are 24 hour windows: one is the window starting 2 days ago, then there’s one starting 24 hours ago, then there’s the one predicting the upcoming 24 hours, and so on).

It allows you to check how your routes have performed in the past, and to filter out those routes that have an acceptable occupancy level already.