I am having trouble finding the answer for this.

I leave my computer running over night. If updates are required, I would like them to happen at night, so the games are available when I am ready to play. The steam auto-scheduling choices of two to three days after an update release does not work for me.

How do I change the scheduled updates such that, if an update is available, it downloads between the times I have set, rather than waiting a couple days?