From Latin horaius, the term schedule refers to what is related or that belongs to the hours . Its most common use is linked to temporary period during which an activity is carried out.
It is evident that, to understand the notion of schedule, one must understand the concept of time. This physical magnitude measure What is subject to change. When something changes from one state to another, the period elapsed in that process can be measured in a unit of time.
Time, in turn, can be measured through the use of a clock . The purpose of establishing a schedule, for example, is to indicate the precise moment in which a future event will take place so that people can organize their routine.
The time change
One of the concepts most closely linked to the schedule is that of DST (Daylight Saving Time or time for saving solar light) that is done at a certain time of the year in most countries; it contemplates the daylight hours that a day has and stipulates a fixed civil time where it is intended that citizens can have the most hours of light natural on your workday, so you avoid absurd electricity expenses.
The time change is mainly linked to economic issues and was first proposed by William Willett, an English builder who in 1905, while riding a horseback ride before breakfast, thought about the amount of Londoners who were still sleeping, when he already Sun He had left several hours ago; In addition, being fond of golf, he disliked shortening his route because of the sun's fall.
He then proposed to advance working hours, but to make it less abrupt, he recommended going ahead of 20 minutes per week, taking into account the sunrise and sunset, so that they could make the most of daylight hours. His project was not approved until 1916 by the Germans, the first to apply daylight saving time. Later they did other countries in Europe, and later Russia and the United States.
At present the time change implies a saving considerable energy. In Spain, for example, it is estimated that it becomes up to 5% in the domestic sector; for this reason it is said that the reasons that drive it are economic, although it also includes other benefits, such as caring for the environment and the use of natural resources.
Not all countries have adhered to the time change, although almost all of those in the Northern Hemisphere of the planet. It is believed that one of the things that boosted its use in the various countries had to do with the first oil crisis that was lived in the world in 1974, as a way to make better use of the electricity.
The Earth is divided into 24 areas (which cut it vertically and horizontally); Each one represents a time zone. According to the location of each country in the planisphere, it will belong to one or another area.
They are called spindles because each area It has a similar shape to spindle spindle. With respect to their arrangement, they are centered on meridians that have a length that It is always a multiple of 15 °.
Before they existed, in each city the schedule was measured based on the location of the sun and they came into existence minute differences between cities that belonged to the same region; With the implementation of the time zones, this problem was solved, by synchronizing all the clocks in the same area.
In turn, the schedule of each region is set by the so-called coordinated universal time (UTC), centered on the greenwich meridian, whose area 0 includes London. When we move from one place with a time zone to another with a different one, we must: add one hour if we go to the east and subtract one if we go from EAST to WEST. When the meridian is crossed, that is, 180 ° of the earth's surface is crossed, then the hourly change will be 24 hours.