When flying overseas (or crossing many time zones), some people suffer jetlag. There are a number of things one can do to help alleviate or minimize the effects of jetlag: food and fluid intake, modifying your sleep schedule, and drugs created particularly for this purpose.

But since the commercial airline clearly knows where you're heading, they can be in an advantageous position to help with this as well. Notice that many times, flight attendants will request all passengers lower or raise the window shades, thus inducing "daytimes" and "nighttimes". I wonder if they time the meals and these shade-down times to help with jet lag specifically?

I would only assume they do. After all, it's just good marketing to have your travellers well rested when they arrive at their destination, instead of them being completely exhausted and unable to adjust. No?