The power company here has some similar programs. One is that on a "peak usage" day (typically during a heat wave) if you keep your use some percentage below your usual use you get a rebate/credit of some sort. I signed up but the problem was that I turn off the A/C and such when I am not home, so my useage on these days can't get any lower than it already is (short of turning off the fridge, which I am not willing to do). So, I've gained nothing from that particular program.
Other programs include ones that cycle the A/C less often (they come attach some meter or something) to save energy on certain days - I haven't noticed any effect of this when I am home on weekends.
In terms of peak use hours - it is easy enough now w/ most appliances to set them to run a couple hours after you go to bed. However, I find some peak use hard to avoid - like the water heater for showers, stove, adjusting the heat/ or a/c when I get home from work so the house isn't sweltering/freezing.