I received a USAF ROTC commission back in 1990. Things may have changed since then, but ROTC is essentially another college course and counts as an elective. There are other responsibilities that you have to undertake as part of the cadet corps, so there is some extracurricular time required and that can be as little as you need or as much as you want.
I hope you didn't wear a
Pledge
Pin on your uniform.....