Can there be more?
And I got to agree with what the writer is asking. Does 1 hour once a year really makes any difference? Is people going to stop using aircon, less driving, less internet and TV after that? Sadly, i dont think so.. It's like a habit that cant change if the people do not really make the effort.
Sometimes, the event just let them think that "Oh, I already did my effort by switching off the lights on 28 Mar", even though they may have been still watching TV, surfing internet in the dark that night. As some people have commented, the event should be held 1 hour every night, not just once a year. But i guess nobody thinks that it is necessary to do so..
As for me, i didnt participate in the light-switching on 28 March. However, what I did do is to remember to switch off the lights/computer/water container heater every night. There was a time when i used to fall asleep in front of the computer, leaving the computer, lights, TV on throughout the night. And I'm glad to say that it no longer happened for the past few years. So i guess all the little things help, if you care to do them. :)