2014 cadet here...
I'd say half of the days follow a schedule with 0500 wakeup. physical training 0515-630ish. Breakfast around 0700. Fill in the day with training, uniform issue, briefings, etc. Lunch at noon. Afternoon is much like the morning. Mass athletics/Corps Squad practice at 1600. (I think...) Dinner at 1800, 2130 is personal time (shower, write letters). 2200 is lights-out, no exceptions. There isn't much down-time at all, but there really is no way to fill in all the time slots exactly. What you can expect in those empty spaces is briefings, PT, waiting in lines, and knowledge parties (stand on the wall and pass off knowledge to the upperclassmen).
The first 3 weeks of CBT are MUCH more predictable (like above) than the 2nd half. 2nd detail is random (to New Cadets, at least). Really early wake-ups for ruck marches, late bedtimes for nights using Night-Vision Goggles. Meals whenever. They really did try to force 7 hours devoted to sleep each night.
