Robots with circadian clocks?

Courtesy of Mind Hacks, we learn that the new issue of The Scientist has a special on robots, particularly on robots designed to emulate particular aspects of behavior (human behavior, of course).

One article in particular is of interest to me as it covers the latest findings on time perception. There is actually not much about robots in that article, nor about circadian clocks, but mostly about interval timing, something I do not know much about although I really want to learn more.

That leads to thinking.....why would one want a robot with a circadian clock? Don't we want robots, and for that matter all our machines, to be able to function optimally at all times of day, no matter how we feel, or if we are awake or asleep? Do you want your computer to be more sluggish at night than during the day? If you take your lap-top on a transcontinental flight, do you really want it to be as jet-lagged as you are?

I set up my virus-detecting software to run a scan every day at 4am - the time of day I am least likely to be awake and using the machine. Wouldn't it be nice, especially for globetrotters, to have the computer "sense" your timing and adjust such scheduled activities to your schedule? It can run a virus scan a couple of hours after you log off after a long period of more-or-less contnious use, for instance. Would an electronic circadian clock be a good way to design such a system or is there a simple algorithm one may devise to "teach" the computer to do this?