我国从今年五月起在全国范围内实行夏时制。以后,每年从四月上旬开始,把时针向前拨一小时,到九月中旬起再向后拨一小时,即重新恢复到原来实行的时制。全年夏时制的时间近五个月。实行夏时制,既可以充分利用自然光源,节约照明用电,又可以使人们养成早起早睡的好习惯,增进身体健康,提高学习和工作效率。为什么在我国要在不同的季节,实行两种不同的时制呢?这主要是我国所处地理位置决定的。我国位于地球上东半球的北半部(或称东半球的北半球), Since May of this year, China has implemented daylight saving time nationwide. Afterwards, from the beginning of April each year, the hour hand will be forwarded for one hour, and by mid-September it will be set back one hour. It will then return to the original time system. The summer time in the whole year is nearly five months. Implementation of the summer time system can not only make full use of natural light sources, save lighting and electricity, but also enable people to develop good habits of early going to bed early, improve physical health, and improve learning and work efficiency. Why do we have to implement two different time schedules in different seasons in our country? This is mainly determined by the location of our country. Our country is located in the northern half of the earth’s eastern hemisphere (or the northern hemisphere of the eastern hemisphere).