Your answer depends on your location on the continent. At the extreme, six months at the South Pole.
There is little or no sun on Antarctica for about six months each year.
1/2 a year
Antarctica does receive sunshine. Because it lies south of the Antarctic circle, there are periods of between 24 hours and six months when there is no sunrise.
Depending on where you are south of the Antarctic Circle, the period of no sunrise/ sunset may be a day or so, up to six months at the South Pole.
Because of the Earth's angle of rotation. There is less winter (March - September) sunlight as you go further and further south into the heart of Antarctica.
nothing
Sweden is the country having six months day and six months night because it is located in the north pole. However I think that Antarctica is also having long days and long nights because it is in south pole.
November, December and January are usually the warmest months on Antarctica. The temperature, however, is rarely above freezing during those months.
Actually, nothing happens to the sun. But at both polar regions, because of the tilt of the Earth toward it, there are periods of no sunrise in winter. This phenomenon occurs beyond 66 degrees of latitude and can last for between one 24-hour period to six months without a sunrise/ sunset each year.
Kangaroos do not and cannot live in Antarctica.
Your answer depends on where you are on the continent. At the Antarctic circle, there is at least one 24 hour period with no sunset. At the South Pole, there are six months with no sunset.