I can make rules time-aware with "Time of Day Sets," and you'll find those under Build --> Groups. These allow you to make rules that only fire in certain time frames, or exclude time-frames. Like, if you know you're going to reboot machines every day at 2AM, maybe you make your "Agent/System Offline" rule inactive between 2 and 4.
However, there's not a way to make a rule fire at the same time every day that I am aware.