I work in surgery where i'm on my feet most of the day. would i still need to do the recommended 30 minutes of exercise a day?

Standing is not : Excercise. In fact people wh stand and don't walk much like a barber run the risk of varicosities and breakdown of valves in veins as their muscles don't get to be used properly.

Time is on your side: One could go crazy just trying to figure out the recommended time for one thing or another. I think the most regarded number is 150 minutes of moderate exercise per week. I would think that is at a minimum brisk walking. Another parameter used is walking 7000 steps per day. Either way, don't get hung up on the number. Recognize that you daily routine is having some effect and continue to do more.

Consider stretching: exercises such s yoga or even Chinese qigong. Loosen up those muscles that are held tense during your hours in the OR. Thank you for your good work. Peace and good health.