Changing Activity Level Based on the Day?

So I have a bit of a dilemma I've been trying to figure out. I'm currently a nursing student which means that I spend about 4-5 days a week being sedentary (doing homework/being in class) and 2-3 days a week on my feet doing physically demanding things for 12 hour days in clinicals. Since I kind of have both extremes of "sedentary" and "active" during the week, should I change my activity level based on the day? I have tried just adding my clinical days as exercise like "360 minutes of walking, moderate pace" (6 hours of the 12 because I do sit sometimes). Doing this always adds TONS of calories to my daily limit. It is really hard to determine exactly how much I've been moving around during a clinical day so I normally just estimate when I put it in as exercise. I have tried a fitbit to track activity, but anytime I'm pushing beds or something it doesnt count steps, and it also just gets in the way a lot. I'm wondering if it makes more sense to just flip my activity level back and forth throughout the week based on what I'm doing that day. Thoughts?