Where does the time go?

21. Exercise more. My mother has offered to give me her treadmill and I am planning to buy the computer rest you can use for them so that I can type or surf the web and walk so I at least get a little exercise.
I added it up.  I spend…  9 Hours at work sitting
                                    2-3 Hours at school sitting
                                    2-3 Hours at home doing homework or sitting with my dog
                                    11-13 hours
                                   minus 8 hours of sleep.
                          Leaves me 3-5 hours a day that I am not sure what I have done with.      
This is probally the cooking, cleaning, driving to somewhere, ect.. hours but I still should have time to get a bit more done then I have been lately. I am not sure where my time has gone. I really want to start exercising a bit if only to make myself feel better. I am almost always tired and I refuse to buy any more clothes in a size larger then I am at now. I cannot wait till I am out of school so that I have my afternoons free, then I can lease a horse again and start riding five days a week again. 
Where does the time go?