why does daylight savings still exist in the United States?
In the United States, the economy used to be heavily based on agriculture.  Therefore, daylight savings was originally instituted to facilitate a farmer's workday so that much of the working hours could coincide with the hours where there was more daylight (daylight begins is later in the spring). Since then; however, the U.S. economy has become less agriculturally based and also with technological advancements that have drastically impacted American work patterns, the need to follow daylight windows has reduced dramatically. While daylight savings still allows many Americans to spend their working hours during the daylight, there is the popular opinion that daylight savings should no longer be observed in the United States, especially with the confusion that comes with changing hours during the spring and fall.  There are at least a couple states that do not change times for daylight savings which further adds to the confusion.
Por que ainda existe o verão nos Estados Unidos?
Nos Estados Unidos, a economia costumava ser fortemente baseada na agricultura. Portanto, a economia de luz do dia foi originalmente instituída para facilitar o dia de trabalho de um agricultor para que grande parte das horas de trabalho pudesse coincidir com as horas em que havia mais luz do dia (a luz do dia começa mais tarde na primavera). Desde então; no entanto, a economia dos EUA tornou-se menos baseada na agricultura e também com os avanços tecnológicos que impactaram drasticamente os padrões de trabalho americanos, a necessidade de seguir as janelas de luz do dia diminuiu drasticamente.