I am an SDA and keep Saturday as the Sabbath. I am also less than a month away from 3rd year starting, so we are in the same position. Now, I'm not trying to turn this into a debate on theology or something, but I'll share how I am going to approach the situation, which may be different from how you practice your faith, but that's ok, this is just my opinion.
The silly thing about humanity is that it never stop having babies, never stops getting infected, never stops being stupid, etc etc etc... If you'll remember the story in Mark 3:1-6, Jesus took a lot of crap for healing someone on the Sabbath. But He turned around and said something that seems like common sense to me. If you find someone in need, are you going to ignore him or her just because it's the Sabbath? As future physicians, we are receiving an incredible amount of knowledge and training we can use to do just that: help out our fellow man. So I personally have no problem with doing some rotations on the Sabbath, or shifts as a resident. You won't find me waking up to study or do some Qbank questions if I have a Saturday off, but I feel like going in to heal like Jesus did is a more than acceptable use of the Sabbath (even if I'm just going to be a scut monkey or something). It's not a rationalization or compromise, I truly believe that's where I should be!
Maybe you feel differently, and that's ok, just thought I would share my view on the matter