Missy,
My3sons did a great job of answering you.

In looking at the "Learning Through History" side of the page first, we're coming up with approximately these time allotments:
Reading About History Box: 30 min.(Indpendent)
Storytime: 20 min.
Project/ Written Narration Box: 20 min.(Independent)
Bible Quiet Time: 20-30 min. (Independent)
Independent History Study: 15-20 min. (Independent)
In looking through the "Learning the Basics" side of the page next, we're coming up with approximately the following time allotments:
Geography/Genesis Study: 20 min.
Poetry: 15 min.(Independent)
Dictation: 5 min.
Grammar or Write with the Best: 20 min.
DITHR: 30 min.
Math: 30 min.
Science: 30 min. (Independent)
This equals 270 min. a day, if all subjects were done each day. Grammar, dictation, Write with the Best and DITHR actually rotate through the language arts box, which means they aren't all done every day. This will lessen the overall daily time. Any boxes that are meant to be independent have 5-10 extra min. built into the time allotment above due to the fact that when kiddos are doing something on their own, it often takes longer than anticipated. So, we've built time in for that!
We found with Preparing Hearts that it took a little while to get into a routine, and then the time dropped back substancially as the year wore on and my son knew what to expect.

So, you can anticipate after the initial training of getting into a routine with CTC that your child's time will drop back as the year progresses.
Blessings,
Carrie