Actually I have read this too. I use to turn off the light and CO2 for about 2 hours during the middle of the day. I do not know if there was a difference or not.
Of course a shorter lighting period would mean less time for photosynthesis, and therefore less algal growth, but less growth for other plants as well, and doing it during the day (when most people are out) would be a sensible time to do it. The question is whether it would have more of an adverse effect on the algae. I would guess not.
I'm probably just stating the obvious...