When I was a kid, I was told the reason for daylight savings time was “to help the farmers,” but that’s not the case at all (in fact, it doesn’t really affect farmers – their day revolves around the sun, so any artificial time we apply is totally irrelevant). The “real” reason for having daylight savings time is “energy conservation.” The idea being that by artificially making sunset one hour later, we get an extra hour of sunlight in the evening, and thus don’t need to turn our lights on as early. In the summertime, the sun would normally rise much earlier than most people, so the need for lights is offset in the morning this time by the fact that most people will still be asleep.
However, there are plenty of problems with daylight savings time, and I don’t think the (somewhat marginal) benefit described above is offset.
The first problem is that I don’t think there is all that much difference in energy saved. Sure, back in the days when daylight savings time was introduced, hardly anyone had air conditioning in their homes. But these days, and especially in warmer countries like Australia, air conditioning is pretty ubiquitous. So the energy saved from lighting will be offset by the energy required to run the air conditioning for longer (because the sun is up an hour longer, it takes an hour longer to cool down again).
Obviously, the other problem (and this is a little harder to quantify) is simply the fact that you have to adjust your clock twice every year. All the effort that is spent reminding people, all the people who end up being late anyway, all the people who are less productive (because they’re so tired) after the change, and so on. These are not so easy to quantify as the cost of air conditioning, but it’s obvious there must be some cost there.
To be honest, I actually like daylight savings time. I don’t wake up all that early (7:30am usually, to start work at 9am), but I get home quite late (finish work at 6pm). So in winter, it’s already dark by the time I finish. I’d be quite happy for daylight savings time to be the permanent time.