日没 meaning in English

[天文学] sunset

This macro computes the length of the day , from sunrise to sunset
把根据要求确定出来的日出日没间隔作为我们通常直觉上的一个白天。
Next , integral again from the sun - rise time to down , it is the one whole day diffuse radiation amount
最后从日出到日没时间段进行积分，得到散射辐射日总量。
The twilight before sunrise and after sunset is due to the scattering of sunlight by the atmosphere . the time of begining and end of twilight depends on the local geographic and climate conditions
日出前和日没后的一段时间内天空呈现出微弱的亮光，这现象叫做晨光和昏影，这是由于大气的散射所引起。