Your sentence is correct.
Ignoring the effects of atmospheric refraction, the sun is above the horizon from about September 21 until about March 21, as seen from the south pole.
The North Pole is dark for six months- from the September Equinox (September 21) to the March Equinox (March 21).
Britain is in the northern hemisphere, the South Pole is at the dead centre of the southern hemisphere. If Britain is in the middle of its summer, the South Pole will be in the middle of its winter, therefore, the South Pole will be in darkness.
The sun sets at the South Pole about March 21 and does not rise again until about September 21. This means that on 21 June, there is no sunrise -- or 24 hours of darkness on that date.
In the North Pole, winter occurs from late September to late March. In the South Pole, winter takes place from late March to late September. Both poles experience continuous darkness during winter due to their axial tilt away from the sun.
North pole have no sunshine at all from September 21 until March 21. South pole have no sunshine at all from March 21 until September 21.
An observer standing at the South Pole would see the sun set below the horizon on March 21, and wouldn't see it rise again until September 21.
Ignoring the effects of atmospheric refraction, the sun is above the horizon from about September 21 until about March 21, as seen from the south pole.
The South Pole has about 6 months of continuous daylight from September to March, followed by about 6 months of continuous darkness from March to September. During the period of darkness, the South Pole has no direct sunlight for about 4 months.
There is no place on the surface of the earth where the sun never sets. As seen from the North Pole, the sun is above the horizon continuously from March 21 until September 21. As seen from the South Pole, the sun is above the horizon continuously from September 21 until March 21.
The North Pole is dark for six months- from the September Equinox (September 21) to the March Equinox (March 21).
Britain is in the northern hemisphere, the South Pole is at the dead centre of the southern hemisphere. If Britain is in the middle of its summer, the South Pole will be in the middle of its winter, therefore, the South Pole will be in darkness.
At the south pole, December is the middle of a continuous period of light that began on September 21 and lasts until March 21. Since December has 31 days, there are 744 hours of daylight there in December.
There is one sunrise at the South Pole each year, which occurs about September 21. From then until about March 21, there are 24 hours of daylight every day until the sunsets. This is caused by the Earth's tilt of the Southern Hemisphere toward the Sun.
There is one sunrise each year -- about September 21, and one sunset per year -- about March 31, at the South Pole.
It depends where on Earth you are.-- Between the equator and 66.5° south latitude . . . June 22-- Between the equator and 66.5° north latitude . . . December 23-- Between 66.5° south latitude and the south pole . . .The sun doesn't rise at all from sometime before June 22 until the same length of timeafter June 22.-- Between 66.5° north latitude and the north pole . . .The sun doesn't rise at all from sometime before December 23 until the same length of timeafter December 23.-- At the south pole . . .The sun doesn't rise at all from March 21 until September 22.-- At the north pole . . .The sun doesn't rise at all from September 22 until March 21.-- On the equator . . .There are two shortest days every year: March 21 and September 22.
You're describing an Equinox -- either March 21 or September 21.