Daylight saving time
“”I was going to say that we should stop daylight savings time because every time it comes around I'm confused for MONTHS. But what we should REALLY do is just standardize all American Time, so there aren't different zones. That way, I could call my brother in Louisiana in the early evening and not worry about him already being asleep because its two hours later there.
|—America Speaking Out
“”If you will try it [DST] out personally, observing the hours that govern the city clerk or laboring man, I believe that you will decide that God knows more about time than President Wilson does.
|—C. W. Browne
Daylight saving time (DST), more accurately called Daylight losing time, is the practice of advancing clocks during summer months by an hour, which will give you an extra hour of sunlight in the evening, while sacrificing normal sunrise times. Clocks are then moved back by an hour in the autumn.
More sun, just for the hell of it
The largest claimed advantage is that you have an hour more sunlight to do fun stuff with (unlike sitting inside and editing RationalWiki). In some temperate regions, in late spring/early summer, the sun starts to rise at about 4 AM (depending on where you live) when most people are fast asleep, and sets at about 8 PM, when most people are still awake. By shifting the time one hour forwards, the sun rises at 5 AM, and sets at 9 PM, so some people have an "extra hour" of daylight to spend. This is, by far, the best argument in favour of DST, and always has been since it was first proposed. Some Kiwi wanted more daylight to collect insects and sent a paper to the Royal Society of New Zealand proposing DST "so as to bring the working-hours of the day within the period of daylight". Independently, a Brit also proposed DST for the same reason citing "nearly everyone has given utterance to a regret that the clear bright light of early mornings, during Spring and Summer months, is so seldom seen or used." Often opponents of DST cite that it's "just for bogus energy savings," which is a bit of a straw man since this usually cited as a possible extra advantage, not the main advantage. DST started well before there was any push to conserve energy.
However, as these arguments are pretty unconvincing, many countries are considering doing away with the silly process completely. 
Since people have one more hour of daylight (and thus switch on the light an hour later) DST will save you one hour's worth of lighting energy. This was an important reason for a number of countries to implement DST during both WW I and WW II. At the time lighting was a significant part of total energy use, but today air conditioning, heating, refrigerators, and such use far more power. It's estimated lighting uses about 3% of all energy.
In more recent years a number of studies have been undertaken to examine the effect of DST on energy usage, and the results are inconclusive. Some report a slight increase, others a slight decrease, and others no significant change. The biggest variable is probably climate: as mornings are the coolest part of the day, you lose up to an hour of air conditioning.
The alleged energy savings of DST drove the US government to enact year-round daylight saving time during the OPEC oil embargo of 1973. This was repealed the next year, however it did lead to DST being moved up by 3 weeks. The US extended daylight saving time an addition 3 weeks starting in 2007.
Reasons not to do it
- Fuck, it's confusing![citation NOT needed]
- Also it (probably) kills people. The disruption in circadian rhythms caused by the time changes is linked to heart attacks, vehicle accidents, and work-related injuries, as well as general lost productivity (due to people being half-asleep).
“”I've always had a hard time getting up when it's dark outside.
But in space, it's always dark.I know ... I know.
|—Ivanova and Sinclair
Permanent DST means putting the clock forward, and never changing it back. It has the same advantages as DST, but without the twice-yearly confusion of mucking about with all the clocks. It has the obvious drawback that in the winter the sun will rise an hour later. Russia tried this in 2011, but soon discovered that a 10am sunrise and getting up in pitch darkness is not ideal either. Having its fill of the whole DST thing after the debacle, Russia repealed all forms of DST in 2014.
Just get up earlier
DST is sometimes presented as a deception or restricting personal freedom since it "cheats" or "forces" you in getting up an hour earlier, so if you want to use the maximum amount of daylight, you should just get up an hour earlier.
This might sound nice at a glance, but the practical implications of "getting up earlier" can get rather messy. While more flexible working times have been gaining traction for office jobs, most people do not work in offices (and even in offices, it's hardly standard), so a company will have to make a decision whether to observe DST. If you do "observe DST" you may find that the shop where you get breakfast/lunch before work isn't open yet, or that the bus times are different. In theory, shops and transit times could also observe DST. It would also be unlikely that there would be an agreement on when to enact DST, leading to situations where public transit will enact DST a week later than a company. In other words, the confusion would be far larger than with a nationwide DST.
- John Oliver gets it wrong
- Daylight Saving Time: Why The Monday After Springing Forward Is A Deadly Day