I am in the same boat as you, I work 6-2, and then go straight to school, even though classes don't start until 4 (parking is a B****). For me tho, I have the advantage of not having class everyday...but i've been close before. My suggestion: Do the weekend. If you feel like you need to do something, there are exercises designed to be 15 min done at your desk, and you could always do a set of x # of reps of crunches or hand weight lifting just before you go to bed. When in doubt, watch your calories, walk the long way" at work (ie the stairs or the longest way possible to the bathroom) and exercise on the weekends. Anything is better than nothing!
H: 5'4" Start: 10/1/10