Steam

There's this game I'm trying to download, and it's big enough that it's going to take several days of continuous downloading to get. I have about half of it so far. I want it to download during my scheduled auto update hours, and pause in the morning when I wake up. Sounds simple, right?

Problem is, it won't. I can either drag it to "up next", in which case it downloads immediately, or I can drag it to "unscheduled", in which case it won't download at all, even if I leave my PC on all night. I can't click and drag it into the scheduled category. How do I get it in there so it'll download when I'm asleep, but won't hog the pre-bedtime bandwidth?