History of Daylight Savings Time
Daylight Savings Time
The DST is the convention of advancing clocks one hour during the summer, in order to increase the sunlight in the late afternoon at the expense of the early morning. Typically, the forward displacement occurs in early spring, to be canceled in the fall.
In contrast, the time base used by each country, when the time coincides with the reference time zone, called "solar time" or "conventional civil time." In some countries the time of day is in fact suspended, whichever daylight saving time throughout the year. It must be noted that the terminology used in other countries is more direct, referring to the summer, or 'summer schedule. " A more accurate name, which mimics the American one, is to "daylight savings time" (daylight saving time), where he was left out the reference to summer.
Already in 1784 Benjamin Franklin invented the lightning rod idea published in the French daily Le Journal de Paris. Franklin's reflections were based on the principle of saving energy but did not find below. Over a century later, in 1907, the idea was taken up by the English builder William Willett, and this time he found fertile ground in the context of the economic needs caused by World War: in 1916 the House of Commons in London gave the go-ahead to the British Summer Time, which involved the movement of the hands one hour ahead during the summer. Many countries followed suit Great Britain as a wartime energy conservation was a priority.
Since 1996, all EU countries adopt the same calendar for daylight saving time, despite the polemics of some member states. They also joined in Switzerland without being part of the Union.
Daylight saving time, according to this timetable, it lasts seven months per year, starts on the last Sunday in March and ends on the last Sunday of October.
In the transition from winter to summer time, when you take the hours of 2:00 am Berlin moves the clock forward an hour, that is the hour that starts at 2:00 and ends at 3:00 is suppressed . In the reverse pass, when taking the 3:00 am hour will return the clock back an hour, that is the hour that starts at 2:00 and ends at 3:00 is repeated twice.
We chose this time because it is one in which the movement of trains and other public transportation is minimized and then minimize the mismatch to the schedule daily schedule. Note that the DST shots synchronously throughout the Union, if the change is therefore between 2 and 3 in Central Europe, is between one and two in Britain, and between 3 and 4 in Greece.
In general, the countries of the tropics do not adopt daylight saving time, since the change in daylight hours during the year is minimal and does not have enough hours of daylight in the morning in order to justify a shift in hands forward by one hour to add light in the evening.
In the southern hemisphere, the seasons being reversed from northern hemisphere, the DST also follows a calendar reversed in Australia is in force from October to late March or early April, with variations from state to state, while in Brazil you go from the third Sunday in October to third Sunday in February.
In Africa daylight saving time is poorly used, as well as in Asia, where it is used in the Caucasian republics of the former Soviet Union, but in many states because the calendars are not homogeneous.
Advantages And Disadvantages
The purpose of DST is to produce energy savings due to less use of electric lighting. Daylight saving time can obviously not increase the hours of daylight available, but only lead to greater use of daylight hours that are often "wasted" because of the habits of time.
Consider for example a person who sleeps all day from 23 to 7. In summer the sun rises and sets in after the first. So with daylight saving earns an hour of daylight. Therefore using electric lighting for one hour less, saving energy.
In this way, with daylight saving time, from 2004 to 2007, Italy has saved a total of more than 2.5 billion kilowatt hours, equivalent to 300 million euro, as calculated by Terna, the company responsible for managing in Italy flows of electricity on high voltage grid, the savings for 2007 alone amounted to 645.2 million kilowatt-hours. It was noted that, however, increasing the hours of free time during the day, there is a greater consumption of fuel circulating after working hours, before dinner.
The same savings would be achieved by adopting a lifestyle that has time to "centered" with respect to noon (ie from 20 to 4 instead of sleeping from 23 to 7). On these topics, however, trigger psychological considerations that are not under the control of the administration.
In the days immediately following the "return time" (ie the transition from legal to solar time and vice versa), some people complain of noise due to the alteration of the sleep-wake cycle. This is the same phenomenon that occurs in people traveling by air between countries separated by different time zones (so-called jet lag), but in this case the effect is minor because the change of time is one hour and many people not experience any interference.
A survey by Codacons that the Italians are in favor to 50% and 50% against daylight saving. The same survey found, however, that the majority of respondents were in favor of standard time. This solution would use daylight saving time throughout the year, eliminating the hassles associated with the time change: The problem is that in winter, with fewer hours of available light, a slit in front of sunrise and sunset could provide yes an hour more light in the evening, but one less each morning.