I am trying to create an SIR model in Simbiology. I input my SIR as species and then define parameters. But the problem is one of my reaction rates is periodic and depends on time. I keep getting the error "Error evaluating reaction rate (from reaction Infectm) at t=0.0000." I'm also a little unsure of the kinetic laws I should be applying for the reactions. I believe I->R should be mass action, but am unsure of the other ones. If anyone has any insight or suggestions that they think would be helpful I would greatly appreciate it.