What does polar night actually mean?
Polar night is a yearly time period during which the sun doesn’t rise above the horizon. The polar circle is a latitude that in practice matches with Earths axial tilt in respect of the Sun and it marks the border for this phenomena. Due to this this tilt we have different seasons when different parts of Earth receive different amounts of the Suns energy during the year.
In the Northern Hemisphere winter solstice, or midwinter, happens during December 21st or 22nd and likewise in the Southern Hemisphere June 21st or 21nd, this marks the halfway point of the polar night. The more north you are the longer polar night. For example in Sodankylä Finland the polar night lasts for 4 days, when in Utsjoki Finland 52 days. This in practice means that in Utsjoki municipality the Sun can’t be seen for almost two months! During this time the time can’t be told by the sun and these high latitude natural phenomena are expressed by the upper dial of the Rohje watch. When traveling to the North Pole you would experience the longest possible polar night that lasts from autumnal equinox in September till the vernal equinox in March, meaning half a year.
The opposite of the polar night is polar day, also know as the midnight sun. During this time the Sun doesn’t set at all. The Sun can be seen going down towards the horizon and then climbing back up again.