I thought that feature was already built into all phones duel SIM devices. I have a colleague that has business phones with duel sims, his SIM activation timer is built-in.
Anyway look at this link https://www.b4x.com/android/forum/threads/simcard-also-dual-sim.51301/. I do not know what it does, but personally I can't see you being able to shut down a SIM. Now making a SIM silent (no ringing) should be easy enough to do in between certain time. Dropping a call or sending it to the answer phone message is another option too.
EDITED: I believe that there might be a phonestatelistener library too, but I have no idea what that even does.