The difference of sunshine time between summer solstice and winter solstice in different regions is different. The equator is 0, and the greater the difference toward high latitudes, the difference between the South Arctic Circle and its high latitudes is 24 hours.

Take Beijing as an example. On the summer solstice in Beijing, the sunrise time is 4: 47, the sunset time is19: 46, and the day length is 14 hours and 59 minutes. On the winter solstice, the sunrise time is 7: 33, the sunset time is16: 53, and the day length is 9 hours and 20 minutes. So Beijing 20 16 Beijing summer solstice and winter solstice day length difference 14 hours 59 minutes-9 hours 20 minutes = 5 hours 39 minutes.

Sunshine time is a very important factor for perennial plants. Long sunshine means that the daily sunshine time is more than 14 hours before flowering. If the natural sunshine time is less than 14 hours, artificial light supplement is needed. Natural sunshine means that the flowering of this plant can be achieved without long sunshine, but some varieties will be/kl ahead of schedule under long sunshine conditions.