Winter solstice
Finally we reached the winter solstice. The calendar no longer says that the day has waned. Now it says that the day has been moved. Good enough, only by 0 minutes, but already the day after tomorrow, December 24, it will say that it has been increased by one whole minute.
Although if the days get longer the day will start later in the next 14 days. Only on January 6 will the day start at the same time as now. and will then be increased by 15 minutes.
The length of the day is the time between the rising and setting of the sun.
Astronomers use 4 terms for the states of sunrise and sunset namely
- Official (the sun breaks the horizon)
- Civile (the center of the sun is 0-6 degrees below the horizon)
- Nautical (the center of the sun is 6-12 degrees below the horizon)
- Astronomical (the center of the sun is 12-18 degrees below the horizon
The period between the official and astronomical state is called twilight, and the period between the astronomical sunset and sunrise is called night darkness.
The bright nights are when it is dusk all night
In Copenhagen, there are bright nights from 5 May to 8 August.
In Skagen, which is a few hundred kilometers north, there are bright nights from 29 April to 14 August.
In Paris there are approx. 1.000 km south of Copenhagen, there are never bright nights.