Daylight Savings Time (DST), also known as Summer Time or Spring Forward/Fall Back, changes the clocks forward 1 hour in the summer months to give an extra hour of daylight in the evenings, then changes the clocks back 1 hour after the summer is over. Times vary by country and year and some countries may change the date for various reasons. less then half of the countries in the world use Daylight Saving Time and the ones who do may not use it in all regions.
In the United States, Hawaii and Arizona do not observe DST, while the rest of the country does.
No matter where you live on this earth, you experience seasons with different weather, hours of light and ecology at specific times of the year. This is due to the annual orbit of the Earth around the Sun and the tilt of the Earth's axis.
Seasons are typically divided into 4 distinct segments of the year. Seasons in the southern hemisphere are opposite to seasons in the northern hemisphere. Most countries follow similar dates for the change of season, however, a few countries have different dates they mark as the beginning or ending of a season.