Why do clocks go back and forward?

Question

How do you gain and loose an hour, if there is still 24hours in a day?

And why only in some parts of the world and not others, who decided this?

Answer 1

It is basically designed so that we can better enjoy the longer daylight hours in the summer. Without daylight savings; much of the morning sun would be wasted as most people are still asleep. So the clocks are adjusted one hour to shift the naturally longer days to appear that they only make the evenings seem longer and brighter. In reality the changing of the seasons and longer times of sunlight equally stretch earlier into the morning and later into the evening. Using a sundial would prove that. It is a missconception that it precipated out of the energy crises of the 70's as most of the US states had adopted it by the mid 60's. It does though save energy as stores do not have to spend so much on indoor & outdoor lighting during their operating hours as most stores don't open until 9 or 10 but do stay open fairly late into the evening. Additional daylight in the morning is useless in the commercial markets. It was orginally conceived by Benjamin Franklin in the US but is a global phenonan. It is used in most of Europe but as you get closer to the equater the seasonal effects of sunlight are diminished and thus no equatorial countries have day-light savings.

Answer 2

The premise was simple,to conserve energy.During the oil embargo in the early 70's.By changing the peak hours of use to daylight hours.